ByteFall

A browser number puzzle about cracking encrypted data, inspired by Blockchain, the hacker-themed arcade cabinet game in Arcade Paradise.

• Play: https://emptyfishtank-jb.github.io/ByteFall/bytefall.html
• Everything (the landing page: ByteFall first, then THE ARCADE, BYTERRIUM, BYTEFALL VIZ and DEV & TESTING): https://emptyfishtank-jb.github.io/ByteFall/
• Studio: Empty Fish Tank
• Started: September 23, 2026, 8:13 PM CST

Mechanically it's a Drop7-style puzzle:

• Encrypted bits numbered 1-7 fall into a 7×7 terminal, one column at a time (Hard: 1-8 on an 8×8 grid, a full byte).
• A bit decrypts (clears) when its number matches the length of the unbroken line it sits in, across or down (e.g. a [5] decrypts when it's part of an unbroken run of exactly 5 filled cells in its row or column).
• A decrypted bit scores 10 plus its number (a [4] is 14, a [7] is 17). Blocks wiped out by exploits score a flat 10.
• Decrypts chain: bits above fall into the gap and may make new matches. Chains multiply the points.
• Every 8 drops a row of encryption layers ([=]) rises from the bottom. Decrypting a bit beside one peels it down to [-], and a second peel reveals the bit underneath.
• Columns can spill into an overflow row above the ======== line. Decrypts still resolve there (a lone [1] decrypts itself), but anything left above the line afterwards completes the trace and ends the run.

ByteFall Viz

The music player's visualizers as their own app, for whatever the phone plays (Pandora, Spotify, YouTube, ...), with the song from any app shown and played / paused / skipped: visualizer/ (see visualizer/README.md), built by Actions → ByteFall Viz APK.

Byterrium

The CPU bots' own world, with nothing of the game: https://emptyfishtank-jb.github.io/ByteFall/byterrium.html (byterrium.html). It runs on ByteFall's very files (the bots and their minds, the visitors, the weather, the places, the fishing), so the lanes in ByteFall are a preview of it, and a change to either shows in both. Played sideways (made for a phone on its side): held upright it asks to be turned, with a button that goes full screen and locks the screen sideways where the browser allows (or STAY UPRIGHT), and installed from the browser (byterrium.webmanifest) it opens sideways.

• TRAVEL (the button, or T): the places (THE GRID, MEADOW, LAKE, BEACH, WOODLAND, FARM, CITY, DESERT, SNOWFIELD). The bots fade out and back in somewhere new and stay there till you pick another; each place keeps its look, and the bots keep their minds, between visits and reloads.
• The header says where they are, the time, the weather and (at night) the moon.
• In the world mode (window.BYTERRIUM) a place never runs out and the scheduled fog stays away (the weather still comes and goes); ByteFall's scenes still come now and then and pass.

Repo layout

index.html              the landing page (GitHub Pages serves it from the root): a link to each of
                        the games and pages; an old link with ?... on it, or the game installed from
                        the browser, goes on to the game
bytefall.html           the game page (the Android app's index.html: tools/build-app.js)
arcade.html             THE ARCADE, its own page (ARCADE.md)
byterrium.html          Byterrium, the bots' world (js/byterrium.js, css/byterrium.css, byterrium.webmanifest)
manifest.webmanifest    the installed app's name, colors and icons
css/style.css           all the styles and the themes
js/                     the game: script.js (the game itself), player.js (the music player), progress.js (levels, unlocks,
                        achievements, stats), unlocks.js, cpu.js (VS CPU), sfx.js, fx.js,
                        viz.js, grid-bg.js; THE ARCADE's (arcade.html, ARCADE.md): arcade-shell.js, arcade.js and
                        its games, arcade-codebreaker.js, arcade-trace.js, arcade-merge.js, arcade-checksum.js,
                        arcade-defrag.js, arcade-decode.js and arcade-routing.js
js/data/                puzzles.js, daily-puzzles.js
js/music/               music.js (the player), one music-*.js per track, output.js (SOUND
                        OUTPUT, instrument channels), mixes.js (mix tables), archive/
assets/                 fonts/, icons/, audio/ (WAV renders of the tracks, not used by the game)
dev-tools/index.html    DEV & TESTING: every tester and tool, sorted, and the dev switches (dev.css,
                        shared with the landing page)
dev-tools/audio.html    SOUND & MUSIC (sound-scenes.js: every sound and a scene of its moment; the
                        SOUND TESTER's link; tracks-info.js: the track list for it and the mixer)
dev-tools/mixer.html    the mixer, one track at a time (?track=sleep-mode)
dev-tools/bots.html     the bot sandbox: the wanderers, visitors, seasons, fog and headphones on buttons
dev-tools/frames.html   the frame editor: the bots' animations drawn a frame at a time, exported as .json
arena/                  ARENA TEST: a first look at a 3D vehicle arena (TODO.md: WARTHOG ARENA), three.js
                        and cannon-es in arena/lib; not part of ByteFall (the app's build never copies it)
js/data/bot-anims.js    the drawn animations, built in from the frame editor's files (the windmill)
js/pixel.js             PIXEL MODE (the sandbox's switch, for now): the bots on a screen at twice the
                        art's resolution: moves in whole pixels, turns redrawn, hair that flows
js/bot-svg.js           the bots' pixel art (shared by the game and the sandbox)
docs/achievements.csv   every achievement, grouped
STORES.md               the plan for Steam, the Microsoft Store and cars (decisions, work, paperwork)
tools/build-app.js      the Android app's copy of the game (www/): no dev page, no DEV link, build info baked in
tools/setup-android.js  the Android project made ByteFall's: full screen, portrait, back button, version, test key
tools/android/          its MainActivity, icon and splash images, and the test signing key
.github/workflows/      android-apk.yml: builds the test APK on GitHub (Actions → Android test APK)

Android test APK

GitHub builds the game as an Android app (Capacitor) when you ask it to: Actions → Android test APK → Run workflow (pushes don't build it). It's the TEST edition, ByteFall Test (com.emptyfishtank.bytefall.test): its own app, so it installs beside the Google Play version and keeps its own progress. When the run is done, its page has the APK under Artifacts (a zip; unzip it on the phone and open the .apk, allowing installs from that app if Android asks). It's the game as players would get it: no dev page or DEV link, dev switches cleared, full screen, portrait. Its text keeps the game's own sizes whatever the phone's FONT SIZE and BOLD TEXT settings (tools/android/MainActivity.java: the WebView's text zoom pinned to 100%, the activity's font scale to 1 and its extra weight to 0), as games do: the layout is built around them. Every test build is signed with the same test key (tools/android/test.keystore, not a secret and not for the Play Store), so a new one installs over the last and keeps the progress.

SOURCE (asked when you run it): live, the default, is the testing build: it loads the game from GitHub Pages each time it opens (its cache off), so every push to main shows up on the phone with no new APK; offline it falls back to the copy it was built with (tools/live-app.js). bundled has its own copy, as players would get it, and is what the Play Store builds will be (updated through the store). Either one installs over the other; only a change to the Android side itself (tools/android/, the Capacitor setup) needs a new APK. The game knows it's in the app from its user agent (ByteFallApp, capacitor.config.json). The app has no DEV link (the site's footer does). DEV MODE there is the secret tap: FALL three times then BYTE three times on the main menu's title (the Play release keeps it too, till launch), the same flags as the dev page's switch; switched off from either, it's off. It switches in place, no reload (Unlocks.setDevUnlock tells the game, as a purchase does): a reload in the live app could land on a stale copy. For testing, kept through launches. The page's layout class (cards-in-settings) is on <body> in the HTML itself, so a script that stops short can never bring back the old layout.

To build it locally instead: npm ci && node tools/build-app.js && npx cap add android && node tools/setup-android.js, then open android/ in Android Studio (the debug build is ByteFall Test; node tools/build-app.js release for the release edition's copy).

Releasing to Google Play

The Play Store gets the RELEASE edition: ByteFall (com.emptyfishtank.bytefall, the package name in the Play Console), built by Actions → Android release bundle → Run workflow as an Android App Bundle (.aab, under the run's Artifacts) to upload in the Play Console (Testing → Internal testing, or another track → Create new release). It's the game with every dev piece out (tools/build-app.js release): no dev unlocks (whatever's in storage or the URL: js/unlocks.js; only the secret tap, till launch), every dev switch cleared, no infection or sound tester or archived tracks. Nor the music player's other sources, OTHER APPS and MICROPHONE: its visualizer shows ByteFall's own music only, with no SOURCE button (js/extsource.js), and its own manifest (android/app/src/release/, written by tools/setup-android.js) takes out the capture service, its foreground service permissions and the microphone's (RECORD_AUDIO, MODIFY_AUDIO_SETTINGS), so the Play Console's foreground service declaration isn't needed and the app never asks for the microphone (MainActivity refuses OTHER APPS without the service, too). The TEST edition, the web and ByteFall Viz keep them. Its privacy policy, for the Play listing, is on the studio's site: https://emptyfishtank-jb.github.io/bytefall/privacy.html (the EmptyFishTank-JB.github.io repo, with app-ads.txt; this repo's privacy.html sends the old address there). Its version code is the build number (?v=), so each upload needs a push after the last. While js/ads-config.js says testing: true the run warns that the bundle shows test ads (fine for a testing track, not for production).

It's signed with ByteFall's upload key, kept out of the repo in four repository secrets (GitHub: the repo's Settings → Secrets and variables → Actions → New repository secret). Made once, on your own computer:

1. Make the key (keytool comes with any Java JDK, and with Android Studio, in its jbr\bin): keytool -genkeypair -v -keystore bytefall-upload.jks -alias upload -keyalg RSA -keysize 2048 -validity 10000 (it asks for a password and your name; the key's password can be the same one).
2. The file as text: on Windows (PowerShell) [Convert]::ToBase64String([IO.File]::ReadAllBytes("bytefall-upload.jks")) | Set-Clipboard; on a Mac base64 -i bytefall-upload.jks | pbcopy.
3. The secrets: UPLOAD_KEYSTORE_BASE64 (that text), UPLOAD_KEYSTORE_PASSWORD, UPLOAD_KEY_ALIAS (upload) and UPLOAD_KEY_PASSWORD.
4. Keep bytefall-upload.jks and its password somewhere safe (a password manager), never in the repo. Google Play keeps the app's real signing key (Play App Signing) and re-signs each upload, so a lost upload key can be replaced through the Play Console, but it takes a few days.

The STORE's purchases (js/billing.js, MainActivity's PURCHASES; Google Play's billing library, added by tools/setup-android.js, which brings the BILLING permission the release checks look for). Set up once in the Play Console:

1. A payments profile (Monetize with Play → Products asks for it: bank account and tax details). Google verifies it, which can take a few days.

2. A bundle with billing uploaded to a testing track (the Play Console only lets products be made after one is).

3. Monetize with Play → Products → One-time products, three, each made active. The IDs are for good (never changed or reused) and must be exactly these:

   Product ID	Name	Price (US)
   remove_ads	REMOVE ADS	$1.99
   full_access	FULL ACCESS	$4.99
   full_access_upgrade	FULL ACCESS (upgrade)	$2.99

   The upgrade is offered only to those who own REMOVE ADS (the STORE picks it), at the difference, so nobody pays more than $4.99 in all. Google Play sets each country's price from the US one.

   A fourth, never sold, is the PRE-REGISTRATION REWARD: day_one (DAY ONE), made the same way and active, then picked as the reward on the game's pre-registration page in Play Console. Everyone who pre-registered gets it as a purchase when they install after launch; the game picks it up with the rest of what's owned (at launch and each return to the app) and acknowledges it, and it unlocks the four DAY ONE themes and the DAY ONE badge (see THEMES). Nothing else to wire up: MainActivity doesn't ask its price, as it's not for sale. Its listing: name DAY ONE: Pre-registration Reward; description Thanks for being here from the start. Four exclusive themes (ZERO DAY, HOLO FOIL, BLUEPRINT and FIRST LIGHT) and the DAY ONE badge on your RECORDS.; icon assets/play/day-one-icon.png (512x512, 32-bit; drawn from day-one-icon.svg beside it), everything within 165px of the middle: Play shows it cut to a hexagon badge with a frame round it. Its words are in the game's default font, Courier New Bold (a render needs the real Courier New installed, as on Windows: a machine without it swaps in a look-alike).

4. Settings → License testing: your Google account (the one on the phone's Play Store), so your purchases go through Google's test cards and charge nothing. Refund one from Order management to see the game take it back at the next launch.

5. In-app updates (js/app-update.js, MainActivity's updateCheck / updateStart / , Google Play's in-app updates library): the release installed from Google Play checks its track for a newer version at launch and on each return to the app. One there, UPDATE shows beside TUTORIAL on the main menu (a notice says so once per version); a tap opens Google Play's own sheet, the update downloads while the game goes on (UPDATING n%), and RESTART TO UPDATE installs it and starts the game again. To try it: install a build from the testing track, then upload a higher one to the same track and open the game (Google Play can take a while to offer it; clearing the Play Store's cache helps). The website and ByteFall Test never show it.

Keys, resources and patches

ECONOMY.md has the whole economy in tables: every resource, how and where it's earned, every price, the BLACK BOX odds and the infections.

KEYS are the game's currency, earned by playing and kept on the device (progress.js): 1 for every 10 bits decrypted, +2 when a chain reaches 5 links and +5 at 7, a first puzzle solve (EASY 2, NORMAL 4, HARD 6), 10 for each achievement and each level, 5 for the day's first daily game, and 25 with the DAILY DROP (plus 3 each of BUGS, CACHE and CRYPTO, and every 7th day in a row you open the game, 3 MASTER KEYS: the LOGIN STREAK, its days and a pip for each day of the run of 7 shown under the DAILY DROP; a day missed starts it over) (claimed once a day in the STORE, with a free exploit for the next game) (the STORE button on the main menu carries the game's currency sign in their corner: unlit, a dark tube, and lit like a HOT NOW sign, glowing with a slow hum and a flicker now and then, while the DAILY DROP waits). Beside them, the RESOURCES, earned by how bits are decrypted: BUGS (down a column, 1 per 5), CACHE (across a row, 1 per 5), CRYPTO (each chain link from the 3rd on), ROOTKITS (a bit decrypted across and down at once, layers broken, BYTES) and MASTER KEYS (every 5th level, the day's first daily game, the day's first VS win). CLASSIC and DAILY earn them all, BLITZ and ZEN at half the rate, VS only CRYPTO, ROOTKITS and MASTER KEYS, PUZZLE none. Each holds at most 999 (KEYS have no cap). Each has its own color in every theme (BUGS roach brown, CACHE light gray, CRYPTO Bitcoin orange, ROOTKITS red, MASTER KEYS gold with a glow; KEYS the theme's accent; PAPER darker, MONOCHROME in grays). The main menu shows them in a line 8px under the level bar, KEYS first, the STORE too (its [i] by the title, or a tap on that line, opens a card of each resource and how it's earned; each STORE section, PATCHES, EXPLOITS (TIER I) and BLACK BOXES, has its own [i] saying what that kind of thing is, its note kept to a line); a drop that earns some floats them up off the board, and the result screen lists the game's haul. PATCHES (boosters, BOOSTERS in the code) cost KEYS; EXPLOITS (for a game) and BLACK BOXES cost KEYS and resources (a MASTER KEY buys any exploit outright):

Patch	Keys	Does
HEAD START	15	the CHAIN METER starts half full, and holds through drops that decrypt nothing until the first that decrypts something (on an empty board only a [1] would), so the head start isn't lost to the first drop
FIREWALL DELAY	20	the first encryption layer rises 4 drops later
LOOKAHEAD	15	the next bit shown for the first 60 seconds of play
OVERTIME	20	+15 seconds in BLITZ
ANTIVIRUS	25	the next infection a BLACK BOX lets out is quarantined (the box's slot shows the virus, grayed, and passes); bought in a game with infections running, it clears them all at once instead (RANSOMWARE's freed bits settle at the next drop; KEYS demanded, dropped)
RESTORE POINT	40	when the trace completes, the system rolls back: everything above the bottom 3 rows is wiped and the game goes on (once a game); also free for a rewarded ad, once a day (below)
HINT	10	PUZZLE: lights the column the next bit goes in (worked out by js/puzzle-sim.js)
UNDO	8	PUZZLE: takes back the last drop, even after running out of bits

The first six are switched on from the main menu's PATCHES button (the USB stick, then as VS's settings: PATCHES: NONE ON, or the names of the ones on, HEAD START / LOOKAHEAD, filled while one's on; up to two patches a game, BOOSTS_MAX), which opens a card of the ones owned for the mode ("Activate up to two starting patches to use in your next CLASSIC game..."), each with its icon, how many and ON / OFF (a third switched on takes the place of the first), and GET PATCHES (the STORE's); per mode, for the modes they fit and paid for at a game's first drop (RESTORE POINT only when it saves you); HINT and UNDO sit under a puzzle's drop buttons, and with none owned a second tap buys one. Never in DAILY or VS. A patched game says so on its result screen (PATCHED: and their names).

THE STORE's top (store.js), fixed over its list, 8px between each line: STORE [i], YOUR RESOURCES, the resources on one line with KEYS first, then PRICES TODAY (ECONOMY.md's Prices that move): a five-step gauge from LOW to HIGH (green when low, red when high) and why (the year's sale days first: BLACK FRIDAY // 35% OFF EVERYTHING, CYBER MONDAY, the HOLIDAY SALE, NEW YEAR, PI DAY, PROGRAMMERS' DAY, HALLOWEEN's BLACK BOXES, ECONOMY.md; else WEEKEND SALE // 15% OFF EVERYTHING, FLASH SALE // 25% OFF BLACK BOXES, HIGH DEMAND // 10% UP ON EVERYTHING, YOUR DEAL // 10% OFF, or NORMAL PRICES TODAY; a DECRYPTOR rank adds (DECRYPTOR +10%): each rank earns 5% more XP, KEYS and resources and prices rise 5% to match, ECONOMY.md). What a buy says (BOUGHT // ...) shows under the gauge, taking no room till then. Under the ===== line the list scrolls as one: the DAILY DROP, PATCHES, the EXPLOITS (TIER I, TIER II and TIER III, each its own head, split by ----- lines as one category), BLACK BOXES (with BUYER BEWARE) and SUPPORT THE GAME, each category under its ===== line; every item whose price is off today carries its own -15% / +10% badge by its name. A locked exploit is dimmed under a padlock centered on it, its UNLOCKS AT LV n bright; a tap anywhere on it pulses that line, as the main menu's can't-do line does. GET PATCHES and BUY EXPLOITS scroll to theirs. REMOVE ADS is only the STORE's own item, its BUY button (no link to it anywhere else). A sale or HIGH DEMAND is also said once a day on the notice line.

WATCH AD (the Android app only; adPerDay on a patch, store.js, ads.js's RewardAd): RESTORE POINT's STORE card has a WATCH AD button on its left, level with BUY on its right (a patch's price has no resources to show there): a rewarded ad, the player's choice, that gives one RESTORE POINT once it's watched through (closed early, nothing; Google's word decides), once a day (the UTC day, as the dailies; bytefall-ad-rewards), so its 40 KEYS still mean something. It says FREE // 1 TODAY, LOADING... while the ad's fetched, then TOMORROW. Offered with or without REMOVE ADS (that takes the banner away; nobody has to watch one), behind the same consent check as the banner. Its ad unit is rewardedId in js/ads-config.js (Google's sample rewarded unit till ByteFall's is made).

THE EXPLOIT SLOTS (sideSlots in the code; the left fills first): one each side of the exploit button (CLASSIC, BLITZ and ZEN only), opened by level: the left at Lv 3, the right at Lv 9 (SIDE_SLOT_LEVELS in progress.js; before then the main menu's EXPLOITS shows LV 3 behind a padlock and its card says when the second opens and in a game the slot shows a padlock over its level, so the BLACK MARKET comes a slot at a time). THE PATCH SLOTS (script.js patchSlots; PATCH_SLOT_LEVELS in progress.js): the exploit row's two ends, so the row reads PATCH 1, BLACK MARKET L, the earned EXPLOIT, BLACK MARKET R, PATCH 2. The left opens at Lv 5, the right at Lv 12 (a padlock over the level till then; FULL ACCESS both). Each sells a patch that fits the mode and would do something now (no HEAD START while an exploit waits or the meter's half full, no LOOKAHEAD while one runs or on EASY, no RESTORE POINT while one's waiting), at KEYS and a resource or two (PATCH_PRICES, ECONOMY.md), shown as the BLACK MARKET's are (dashed, the currency sign in its corner, the pips), opening with it and turning over on its own count. A tap opens the BLACK MARKET's window for it (PATCH // APPLIED AT ONCE and what it does now; no MASTER KEYS; NOT NEEDED NOW if it would do nothing); bought, it's applied at once (HEAD START: the meter to half, held till the next decrypt; FIREWALL DELAY: the next layer 4 drops later; LOOKAHEAD: the next 60 seconds; OVERTIME: +15 seconds; ANTIVIRUS: every infection running cleared, or with none, waiting, pulsing, for the next one; RESTORE POINT: waiting, pulsing, till it saves you). It keeps its slot, lit and pulsing, while it works (HEAD START till its hold ends, FIREWALL DELAY till the delayed layer rises, LOOKAHEAD its 60 seconds, ANTIVIRUS and RESTORE POINT till they're used; OVERTIME, and ANTIVIRUS clearing what's running, are used the moment they're bought): no other patch shows in it meanwhile. Used up, it stays in the slot dimmed, with a tick, through the next drop; then the slot shuffles (the reel) to a new patch, its pips counting afresh (a slot with nothing useful to sell tries again after each drop); nothing bought in a game shuts a slot for good. The result screen's PATCHED: lists them. Paused, the whole row (and PUZZLE's HINT and UNDO) dims to the drop buttons' 25% and takes no taps. EXPLOITS for a game (STORE: TIER I, II and III) are exploits of your own, any you've unlocked by level, by tier: tier 1 (RNG, BITFLIP, BUFFER OVERFLOW, TROJAN, PIVOT) 10 KEYS and about 12 BUGS, CACHE or CRYPTO; tier 2 (SWAP, WORM VIRUS, KEYLOGGER, PACKET SNIFFER, BACKDOOR) 20 KEYS, about 17 of those and a ROOTKIT; tier 3 (LOGIC BOMB, HONEYPOT, DICTIONARY ATTACK, RAINBOW TABLE) 30 KEYS, about 22 and 2 or 3 ROOTKITS (ECONOMY.md has each). The STORE shows each with its icon, its price in chips, what's still short of it (its amount pulses red; a BUY tapped without enough flashes it), and USE A MASTER KEY when it's short and there's one. BLACK BOX itself isn't sold; I, II and III are (5 KEYS and 3 CRYPTO; 12, 5 and a ROOTKIT; 20, 8 and 2), a random pull each, their odds on them: an exploit of tier 1, 2 or 3 (any of the tier, unlocked or not) or an (I: 65 / 20 / 3 / 12%; II: 35 / 45 / 12 / 8%; III: 10 / 45 / 42 / 3%). (CLASSIC and BLITZ, not the dailies, ZEN, PUZZLE, VS or the tutorial): a layer broken down to its bit now and then lets out an infected one (EASY 4%, NORMAL 8%, HARD 12%; ), its number as ever but its frame pulsing red and a virus in its corner, the notice line saying DECRYPT IT WITH YOUR NEXT DROP OR IT GOES OFF. Gone from the board by the end of the next drop (decrypted, or wiped by an exploit) it's QUARANTINED, +1 ROOTKIT; still there, it goes off: an INFECTION, any of the six, as a BLACK BOX's (ANTIVIRUS waiting catches it instead). (, ): the SCORE box turns red with a minus by its label, and the points of the drop that clears it count negative too; the score can fall, below 0 even. BEST and the records keep the highest it reached, HISTORY the real one, and lifetime points count only how far the run climbs (, never twice after a fall). One at a time, never two within 8 drops (); RULES says so under the BLACK BOXES. INFECTIONS: OFF in the mode's GAME SETTINGS turns them off. Pick up to 2 on the main menu to take into a game: two of one kind (if you have two) or one each of two. The menu has one EXPLOITS button under PATCHES, as VS's settings are laid out: the terminal icon, EXPLOITS: and the names of the ones in, RNG / BITFLIP (NONE; long names trail off), filled while one's in; locked behind the first slot's level till it opens. A tap opens its card (// EXPLOITS): every exploit and box you own to bring in, how many and ON / OFF / ON x2. A tap puts one in (the left slot fills first; with both full it takes the other's place), a second tap a second of it (if you have two), and the next tap takes them out, as PATCHES' tap on one that's on. BUY EXPLOITS (the STORE's TIER I) and DONE under them; each is used once in the game. In the game, a tap arms an exploit as your next drop, as an earned one, and it's used up (the ones not used stay yours). A box waits sealed (pulsing); a tap opens it: the slot spins like a slot machine's reel for about 1.5 seconds and lands on an exploit, which waits there (a tick in its corner) to be armed when you like, or comes up INFECTED, which glitches red and goes off at once, each infection in its own little LED sign or ASCII display within the bits it takes up (js/infections.js; ECONOMY.md has the table): (an ad in its own frame blocks a column below the overflow line for 3 drops, a CPU pulling faces and its claims marching up it), (the next 3 bits hidden, eyes watching from CURRENT), (up to 3 bits padlocked where they are for 5 drops: they can't decrypt or fall, their little screens fading between a grinning CPU and typing gibberish, each showing its value in brackets and its ransom by a key, 8 to 24 KEYS: every tap on it pays 1 to 8, at random, a -KEYS floating up off it; paid off, the bit's free at once, and if its lock runs out first what was paid on it is lost), (the board's bits shown as flickering junk for 3 drops), a (5 drops' resources stolen, a CPU making off with them on a sign through the overflow row) or (fake alerts over the board for 8 drops, popping up on their own clock with a cooldown between, now and then a burst of 2 to 4, up to 4 stacked at random spots in the grid, each closed only by its tiny X). Each has four looks, one picked at random each time. Infections stack (two infected boxes, two infections); ADWARE, the CRYPTOJACKER and SCAREWARE quietly demand KEYS (10 to 20, never shown; RANSOMWARE's are on its bits), stealing a few on every tap until paid off (then they go) or until their clock runs out, and the STORE's BLACK BOXES section warns of all six. While any's on, a little bot at its laptop types away at a virus in CURRENT's corner. The UNLOCKED / ACHIEVEMENT banners are LED signs of small lights in the game's font (js/led-banner.js; the dev page's BANNER LOOK: DOTS, PIXELS, MARQUEE, CHASE or the CLASSIC box), and ADWARE's AD tag is pixels in the game's font too. A menu over the board (pause, game over) hides the infections' displays. SETTINGS' CRT DISPLAY (OFF / SOFT / FULL, bytefall-crt) lays an old tube over the whole screen: scanlines and a vignette darkening toward rounded corners; FULL adds phosphor stripes, a faint flicker, a slow rolling band and a touch of glow (still on REDUCED effects or reduced motion). A slot taken in empty, or once its starter is used, is the (so it's there whether you bring exploits in or not): a random exploit you've unlocked or, a quarter of the time, a BLACK BOX, marked for sale with the game's own currency sign in its corner (a 0 struck through twice, as a dollar sign is: no one country's), each slot's offer changing every 4 drops on its own count (once the market's open, 4 pips under its icon count the drops left, going dark one a drop; on the last drop what's left of them and the icon blink, and at the turnover the icon rolls through a few others like a reel, ticking once for the whole row, and lands on the new offer; REDUCED effects: it just changes). The slots start in step, and drift apart as their items are bought and used. A tap opens the BLACK MARKET's window: a neon sign of a border in the accent, a tilted, flickering sign-sign-sign in its corner and scan lines over it; the item's icon in brackets and its name (a box's odds under it), then each part of its price as the resource's icon over what you have / what it costs (red and pulsing where you're short), and BUY in the middle (USE A MASTER KEY under it when short of an exploit's price with one). A tap off it, the X, Esc or back closes it; drops wait while it's open. A buy waits in the slot until you tap it to arm (or open) it. Once it's used (the armed exploit dropped, a box's INFECTION gone off; an EXPLOITS starter too), the slot keeps it, dimmed with a tick, through the next drop, then shuffles to a new offer with its pips counting afresh: buy as often as you like. Buying opens once the game's first encryption layer rises (ZEN, with no layers: after 8 drops, when the first would); till then the slots show their offers dimmed, and the window shows OPENS IN n DROPS in place of BUY. A game that used them says so on its result screen (EXPLOITS: ... // BLACK MARKET: ...).

How far KEYS go (a simulation of CLASSIC games on the CPU's own board code: node tools/keysim.js): a game decrypts about 90 to 110 bits, so it earns about 14 to 18 KEYS, or 20 to 23 all in with the levels, achievements, first puzzle solves and the daily 10. That's about one patch, or with the resources a game also earns (ECONOMY.md), two tier 1 exploits or one tier 2, or a few saved up for a game with everything on.

Exploits

Filling the CHAIN METER earns a random exploit from the equipped slots: every link of every chain charges it, and the charge carries over from drop to drop (5 links; 3 on Easy). The exploit waits in the exploit button (under the grid), which glows green and shows the exploit's icon (with a count if more are waiting). Tap it (or press E) to arm the exploit: the button pulses amber and the exploit is your next drop, with no taking it back. Drop it into a column like a bit and it runs where it lands. With nothing to arm, the button opens the menu's EXPLOITS tab:

Exploit	Easy chain	Effect
Worm Virus [§]	5x	Wipes out every block in the column it lands in
Buffer Overflow [+]	4x	Adds 1 to every bit; the top number (7, or 8 on Hard) is re-encrypted under two layers (RANSOMWARE's locked bits sit it out)
Trojan [◈]	4x	Wipes out every block touching the spot where it lands
RNG [?]	3x	Scrambles every bit to a random number: the bits flicker through random values in place (the squares don't move) for about half a second before the new numbers land (RANSOMWARE's locked bits sit it out: no flicker, same numbers, still locked)
Bitflip [↕] (drawn as an arrow icon)	3x	Turns every column upside down
Dictionary Attack [#] *	4x	Every encryption layer on the board loses one level at once
Keylogger [@] *	3x	Shows your next 3 bits for the next 10 drops (NEXT's panel reads [@]:10, the drops left, beside them, the label shrinking to fit in any font; in VS, where the box is half CURRENT's square, the three bits alone)
Backdoor [_] *	4x	Deletes the entire bottom row, layers included; everything drops by one
Rainbow Table [*] *	5x	Decrypts every bit showing the most common number on the board
Pivot [⇆] *	3x	Swaps the column it lands in with a neighbor: pick the column, then tap ← or → (or press the arrow keys), with no backing out once picked; edge columns swap with their only neighbor
Packet Sniffer [~] *	3x	For your next 3 bits, tap CURRENT (or press ↑ / ↓) to pick each one's number
Logic Bomb [!] *	4x	Lands as a [!3] block counting down each drop; at zero it wipes out the 5×5 around it
Honeypot [◎] *	4x	Lands as a trap; when a bit next to it decrypts, every bit of that number within 2 cells decrypts too
Swap (two bits, curved arrows trading them) *

Every exploit is unlocked by level and has to be equipped in a slot (see below).

A drop earns at most one exploit, picked from the longest chain it set off.

Modes

Mode

What changes

CLASSIC / STORY

The main game, on EASY / NORMAL / HARD, endless. STORY: CLASSIC's button, tapped again while it's the mode, flips it to STORY (its label then STORY, a small cycle icon beside it (two arrows round a ring, unlike PIVOT's ⇆), the description saying "Tap STORY again for CLASSIC" and CLASSIC's "Tap CLASSIC again for STORY"), and another tap back; mid-game the flip asks CONFIRM? and starts a new game (goalWanted, storyOn(), bytefall-goal: on is STORY; CLASSIC at first). COMING SOON everywhere (STORY_SOON: the Play release, the test app and the website alike, unless the device has been let in): CLASSIC's second tap still switches to STORY (its description starting COMING SOON.), but PLAY says COMING SOON, dimmed and dashed, and starts nothing (storyLocked); the main menu's story row and the terminal intro stay away, the ARCHIVE tab holds only a coming-soon note and RULES' STORY page says COMING SOON. A developer can let a device in for testing (bytefall-story-key, a secret tap sequence on the main menu, STORY_GATED in script.js; the same again locks it, and the page reloads either way). The terminal intro (storyTerminal, #story-term; its words in #story-term-text): the first STORY game's PLAY (GHOSTS' INTRO still to come, Stories.firstDue) fades the whole screen slowly to black (2.6s; the music fades out with it, Music.hush, its setting untouched) and sets the game up underneath; after a few seconds a terminal cursor pops in top left and blinks, then MOTH's unsigned note types out: the terminal's own line (INCOMING // ENCRYPTED // SOURCE UNKNOWN) at a terminal's pace, the message at a speaking pace (62ms a letter, varied, a breath after each sentence and at commas), a key click for each letter (SFX.termKey, punctuation a duller knock, as ECHOES' SHIP SYSTEM TERMINAL 426 types; the tutorial BOT's blips stay for narration). PRESS ENTER TO CONTINUE follows, plain text with the cursor after it (no button to be seen; a button underneath for keys and screen readers): ENTER (the key, or a tap anywhere; SFX.termEnter) drops the cursor a line, and a second later the terminal goes dark, a second more and the phone lights up with MOTH's first IM (Stories.atStart; the INTRO's email, the archive attached, waiting in its MAIL); the phone put down, the black lifts off the board. A tap, Space or back while it types shows the rest at once; REDUCED EFFECTS shows it all at once. Black in every theme (a light theme's text there a phosphor green). Nothing reaches the game under it while it's up. The ARCHIVE's READ THE INTRO plays it again over the menu, without the phone. : in a STORY game, once the phone's yours (the INTRO behind you), a button top left across from PAUSE (its size and shape, its width matched to PAUSE's, a little phone in it, no words; ) brings up on its home screen (; the phone only ever comes out in a STORY game: the main menu's story button opens RULES & RECORDS' ARCHIVE tab). is a little OS (js/stories.js): a status bar, a screen (an app) and a under it, always there and working, in place of a gesture line: BACK (the screen before; from the first one, the phone put down), HOME (the home screen) and MENU (the apps used lately, a tap going back to one); OK under it, a tap beside it, Esc or back puts it down. Its apps: (the conversations, the newest first: MOTH's, TOLL's from file 10, and a few ordinary texts (a friend, MOM, a city campaign, a bank asking to confirm a purchase, a wrong number); a tap opens a thread whole; an IM coming in plays here, BACK going to the list), (the inbox: the INTRO's email with the archive attached, HALCYON's and TOLL's after their files, and a few ordinary emails, an ad among them; a tap opens one), (every call and voicemail, a tap reading it again), (the seasons and their files, as in RULES & RECORDS), (a folder of THE ARCADE's base games, each in FREE PLAY, no daily game, played on the phone: in a frame drawn at a phone's width and scaled to the screen; the phone's BACK asks the game, which saves and says when ()), and CAMERA, NOTES, MAPS and WEATHER with nothing in them yet. The phone's ordinary emails and texts are in the story doc too (### The inbox), each there from the start or coming in with a file. One mode with one BEST (NORMAL's): STORY is CLASSIC's name wherever the game says which mode it is (the main menu, under BYTEFALL, HISTORY, the result). STORY has (no GAME SETTINGS button): it's played on NORMAL's 7x7 board with INFECTIONS on (from GHOSTS' first call, after file 6), whatever CLASSIC's are set to, and its keys set the pace instead of a difficulty (): each key deeper is harder: its layers sooner (: every 8 drops at 128-BIT, 7 at 192, 6 at 256 and 384, 5 at 512 and 1024, then 4) and infections likelier (8% at 128-BIT, 3 points more each key, up to 20%). is what GHOSTS has ( in , ; everything once GHOSTS is finished), whatever's owned or unlocked elsewhere (the daily free exploit too: only once its exploit is introduced), in four stages: at first (no chain meter, no PATCHES or EXPLOITS anywhere, no side or patch slots); (from file 1: the chain meter earns the introduced exploits; the patches MOTH introduces come 2 each into STORY's own kit, ); (from file 9: TOLL's stock, (3) offers of what's introduced at the STORE's prices, new each key, bought into the kit); (from file 12: what you own from the STORE counts too, if it's introduced, and STORY's menu gets PATCHES and EXPLOITS again, its own choices apart from CLASSIC's (, ): up to two patches switched on and up to two exploits brought in, waiting in the EXPLOIT button from the start, both paid for at the first drop; no BLACK BOXES brought). STORY's bottom row starts empty: the EXPLOIT button only once an exploit's introduced (its place kept till then), and each button that turns up during a game assembles pixel by pixel, a decay run backwards (; what's already there when a game starts is just there; held while the cracked card's up). In a game the side slots are (left) and (right): PATCHES once there's a patch to use, EXPLOITS once there's an exploit or from the BLACK MARKET on (the other an empty space till then), each with the uses this key has left in its corner, in brackets so EXPLOITS isn't the EXPLOIT button. A tap opens its card (): what you have of the introduced ones (the kit's, then your own: ×n), a tap using one (an exploit armed as the next drop, a BLACK BOX opened on the button, its reel landing on an exploit or an INFECTION, a patch applied at once as a patch slot's is; NOT NOW when it would do nothing), up to (2) of each a key, back after GO DEEPER; BLACK MARKET in the card shows TOLL's stock. INFECTED BITS only after file 6 (the first call). What a file (with its messages) introduces shows on the cracked card and in the ARCHIVE (INTRODUCED // BITFLIP, +2 HEAD START IN YOUR KIT), and in NOTICES. GO DEEPER starts the next key on a clean board: every bit of the last one (layers, infected bits, bombs and all) bursts away and any infection running is cured, the next layer a full count away at the new pace; when it tightens, the cracked card's note says so (Its layers come every 7 drops.) and so does the message line (192-BIT // LAYERS EVERY 7 DROPS // CRACK IT AT 3,000). : every STORY game has a key to crack, a score to reach, shown under BYTEFALL (// STORY // 128-BIT: 1,250) and as a thin bar along the SCORE box's foot (this key's way from the last key's target to its own) that lights up from 80%. (, ): the key being cracked is for the story's next file, its strength (the points it takes) that file's, on top of the last key's target. Strengths stagger through a story, the same every time (seeded per story): mostly a little higher than the last (now and then level or a touch lower), now and then a jump of 250 to 600, the one after a jump 100 to 250 lower; GHOSTS runs from 1,250 to about 3,000. A key too shallow for the next file's chapter is a filler, (1,500). : five glyphs of noise under BYTEFALL and an empty, broken bar, till a 5-chain from one drop (, ) decrypts it (128-BIT // STRENGTH DECRYPTED // CRACK IT AT 1,250, the bar filling to where the score's got to), or the key's cracked anyway; found out, a file's strength stays known (, by file, kept in the save). The cracked card says what it was cracked at, and the next key's strength only if it's known (Next: 192-BIT, its strength ENCRYPTED). Reach it and the game holds on a card in PAUSE's place: // 128-BIT CRACKED, +KEYS (the target / 150: 10 on NORMAL), then (the next key, 192-BIT, 256-BIT, 384, 512, 1024, 2048, 4096 and on, the next file's, paying more: its target / 150 in KEYS) or (the game ends there, cracked: the bits fade instead of burning, ENCRYPTION CRACKED in the terminal color, CRACKED in HISTORY). Traced after a crack, the KEYS it paid are kept and the result says how far you got (CRACKED: 192-BIT). (; the seasons in ): each key cracked also brings the next of the story being decrypted, a document from the archive, played on the cracked card under its KEYS the way it would come in (), and what comes , after it: a CALL or an EMAIL on the card under it (an email's head with a chime, its words printed), an IM on the phone a moment after. A FILE prints out, two letters every 22ms with a typewriter's keys under it (its carriage at each line's end, its bell at the last); an IM plays on (below), its messages landing whole, each after a beat about as long as the other end would take to write it (900ms and 20ms a letter from a new hand, 450ms and 14ms a letter for a second from the same one, at most 2.8s; three dots bobbing in their bubble while they type), a chime as each lands (yours a rising pip); a CALL rings (a phone's two tones every 3 seconds, at most 7, till ANSWER; a voicemail doesn't) and its words come at a speaking pace, about 150 a minute (80ms and 52ms a letter each word, a pause at commas and stops), a low phone-line murmur for each, its end with a hang-up click and tones (, , , , , , the same in every SOUND THEME). A tap shows it whole; REDUCED EFFECTS shows it at once; on a short screen the card's note on the next key steps aside for it, and it scrolls inside the card). : 18 FILES in 3 chapters of 6, 19 messages after them (11 IMs, 4 calls, 4 emails) and the INTRO's email and IM (FILE, a document from the archive; IM, a thread on : every IM pops up over the game on a phone screen ( as , ), one size, a phone's 9:19.5 (as tall as the screen allows less room for OK, at most 640px): a status bar (the clock the newest message's time, a punch-hole camera, signal, wifi, battery), the contact (a back arrow that closes it, an avatar: ? till you know them), the thread, a message field and the gesture bar. Each message in a bubble, its sender and time above it on its side (theirs left, yours right), each sender's own color (MOTH the theme's color, TOLL its accent, yours a third, , set apart per theme), rising in at the bottom, older ones pushed up; only that file's messages; a long thread scrolls, and scrolled up it stops following new ones till you're back at the bottom. No caret on IMs. Times written in the doc are kept, the rest are late-night times seeded from the thread (). On the cracked card (the phone coming 0.7s after the crack) and in the ARCHIVE an IM shows as an inbox does: its last message and OPEN THREAD // n MESSAGES, which opens it on the phone whole. MOTH is an (names, avatar, headings, NOTICES, the ARCHIVE's filter) till file 9 is recovered ( in GHOSTS_RULES; that card says CONTACT SAVED // MOTH); an unprompted IM is named by how far you are when it comes. A file's IMs, after any call or email, come as a thread of their own on the phone (, ); CALL, pulsing with ANSWER, then its transcript typed out). Its words are written in and put in the game by (which writes ; never edited by hand), its eight jobs in other modes and THE CUSTODIAN's VS bot not yet in (those files come from keys). A save from before the files (24 TRANSMISSIONS) is brought up to date once (: how far it had got, in files; the INTRO had if it had MOTH's first IM). GHOSTS' INTRO (its email and MOTH's first IM, in the doc) isn't on a cracked card: the IM pops up on the phone at the end of the terminal intro, the board under the black till the phone's put down (, from ; from if the intro's been skipped some other way), and the first key brings FILE 1. Three come between games, once each (after the first trace, a DISCONNECT, or three days away, each once far enough in): a card on the main menu (), kept in the ARCHIVE under OFF THE RECORD. (THE TRACE, THE FOUR, PATIENT ZERO, ) open after it, each 12 files in 3 chapters of 4. Chapters are gated by key depth (: any key, then 256-BIT, then 512-BIT): a key too shallow for the next file still pays its KEYS and the card says only that it's deeper (FILE 9 is under a deeper key than this one. GO DEEPER to recover it), how deep and how strong not given away. A story finished opens the next, picked at once (a NOTICE says so). , RULES & RECORDS' fourth tab (a folder): READ THE INTRO, then the seasons with their progress (SEASON 1 // GHOSTS, 2 / 24 FILES // DECRYPTING, NEW ones counted; a season still to come all ENCRYPTED, SEASON 3 // and noise for its name, what it's about and how far, each as long as what it covers, a tap on it saying only ENCRYPTED), and a story's files by chapter, recovered ones to read again in their own look with what came after them (NEW till read), the rest FILE n // ENCRYPTED, how deep their key is in noise too (every piece of a story is a FILE there, GHOSTS' IMs and calls too; a chapter's depth shown once it's reached), DECRYPT THIS STORY to pick it, and in GHOSTS buttons to show one sender's only (ALL, MOTH, THE ARCHIVE, UNKNOWN NUMBER, TOLL), only for senders already heard from; one sender's shows only what's come in (no ENCRYPTED ones saying which are theirs), and a chapter's name stays ENCRYPTED till one of its files is in, so nothing gives the story away. New ones put a dot on the ARCHIVE tab and on the main menu's story button (in STORY, first on the panel: GHOSTS // 2 / 24, a folder icon), which opens the story in the ARCHIVE. Kept in the save (Progress , with the kit and the unprompted messages had), so RESET PROGRESS starts them over. : the mode's settings in a card of their own (), on one button on the main menu's panel that says what's set (NORMAL // INFECTIONS: ON); PATCHES and EXPLOITS stay on the panel. CLASSIC's card has DIFFICULTY (EASY / NORMAL / HARD, HARD behind its padlock till Lv 8, a tap saying so in the card's title) and (bytefall-infections, ON at first: OFF, no INFECTED BITS; a BLACK BOX can still be infected), each with a line on what it does; BLITZ's has INFECTIONS alone, so BLITZ has no card: its button is the switch (INFECTIONS: ON, lit, or OFF; mid-game CONFIRM? first); the other modes have none, so no button. Mid-game a change asks CONFIRM? and starts a new game. DONE, a tap off the card, Esc or back closes it.

Switching modes mid-run asks to confirm, like RESTART. Each mode keeps its own best score.

Difficulty

Setting	Effect
Easy	Shows the next bit, and exploits unlock at 3x–5x depending on the exploit; NIBBLE bonus
Normal	New encryption layer every 8 drops; NIBBLE bonus
Hard	A full byte: 8×8 grid with bits 1-8; new layer every 8 drops, minus one per 700 points, down to every 4; BYTE bonus

On Hard, every 8 bits a single drop decrypts, chains included, make a byte: BYTE DECRYPTED adds a 256-point (2^8) bonus per byte. On Easy and Normal (and the modes that play Normal rules, all but PUZZLE), every 4 bits make a nibble: NIBBLE DECRYPTED adds a 16-point (2^4) bonus per nibble.

High scores are saved in your browser, one per difficulty (Hard's started fresh when it moved to 8×8).

Notices

Every notice has one spot on every screen: the notice line, the line under BYTEFALL (a game's // CLASSIC // NORMAL, the main menu's // MAIN MENU). An achievement, an unlock, a LEVEL UP, a DECRYPTOR rank, a reward or EXPLOIT READY fades in there over the line's own words, in the ENCRYPTION warning's style (plain glowing words, nothing boxed), holds a few seconds and bursts into pixels; one at a time, the next waiting. Nothing covers the board or the menu. They wait while a card is open, while the title screen or the screen saver is up, and through a game (see the level meter below: what a game earns waits for its result screen's EARNED list). NOTICES, RULES & RECORDS' third tab (the ARCHIVE is its fourth: CLASSIC's stories), keeps every one with when it came, newest first (it says so under its head), the unread ones lit, an ACHIEVEMENT's with what it was for under it; while some are unread, a dot sits on RULES & RECORDS (the main menu's and the pause screen's) and on the tab. The DAILY DROP never pops up: a new day's is in NOTICES and lights the STORE buttons, and claimed, the STORE's DAILY DROP card shows what it gave right under CLAIM. A "can't do that" shows in the title of the card it happened on, the title stepping aside while it pulses, then bursts, as VS's setup has it: HARD still locked or EXPLOITS not open yet where the main menu's // CLASSIC is, LOADOUT LOCKED or SLOTS FULL where the card's // EXPLOITS is. What a drop earns in RESOURCES shows in the CHAIN box (chains earn them), centered between the foot of its value and its bottom edge, every resource on one line at once, shrinking to fit if it must; each icon and its +1 line up by their middles (the number trimmed to its capitals).

Levels, DECRYPTOR ranks and unlocks

The level meter. Through a game the level stays as it was, and nothing earned is announced (LEVEL UP, UNLOCKED, achievements): a game stays clean. Then the result screen's score racks up from 0 (well under a second and a half, ticking higher as it nears the total), and its meter fills with the game's bits, a rising tone as it fills, a little fanfare and a flash at each LEVEL UP (about 1.2 seconds a level, the whole fill over in about 4), and under it an EARNED list of everything the game held back (achievements, unlocks, level ups), each kept in NOTICES too; left another way (MAIN MENU from PAUSE), they show on the notice line instead. A tap on the meter skips to the end. PUZZLE too: its bits count toward the level and KEYS as in any mode, but a puzzle already solved, played again, pays them once a day (its first solve, or a replay's solve, marks the day; another replay that day pays nothing, and the result says so).

Levels. Every bit you decrypt is XP: 100 bits (12.5 bytes) per level, from Lv 0 to Lv 80. Lv 80 comes at 8,000 bits, so a full DECRYPTOR rank is exactly 1 kilobyte. The level bar sits under the title.

Everything unlocks by level, within a rank, by level alone (nothing on this list is bought; an exploit past the first three is then bought once to keep, see EXPLOITS). Every exploit and every slot opens by Lv 50; everything else (Hard mode, the VS CPU's levels and bots, tracks, themes and fonts) by Lv 60. Something nearly every level at first, a few sharing a level; Lv 61 to 80 is the run to RANK UP:

Lv	Unlock	Lv	Unlock	Lv	Unlock
1	RNG, SLOT 1	17	ANAGLYPH	36	SLOT 5
2	BITFLIP, TRACK 02	18	TRACK 07	37	TRACK 12
3	SIDE SLOT L, CIPHER	19	KEYLOGGER	38	DICTIONARY ATTACK
4	BUFFER OVERFLOW	21	TRACK 08	39	PAPER
5	PATCH SLOT L, BOT: GRIFTER, TRACK 03	22	PACKET SNIFFER	40	INSANE CPU
6	SLOT 2, SHARE TECH MONO	23	SYNTHWAVE	42	TRACK 13
7	TROJAN, AMBER CRT	24	SLOT 4	43	RAINBOW TABLE
8	HARD MODE, TRACK 04	25	TRACK 09	44	BYTESIZED
9	SIDE SLOT R	26	BACKDOOR	47	TRACK 14
10	PIVOT	27	BITCOUNT	48	SLOT 6, GLYPH
11	HARD CPU, TRACK 05	28	BOT: GLITCH	50	BLACK BOX
12	PATCH SLOT R, MONOCHROME	29	TRACK 10	53	TRACK 15
13	SWAP	30	LOGIC BOMB	55	ORBITRON
14	SLOT 3, TRACK 06	31	DOT MATRIX	57	SPECTRUM
15	BOT: BUNKER	33	TRACK 11	60	TRACK 16
16	WORM VIRUS, PRESS START	34	HONEYPOT

DECRYPTOR ranks (the game's prestige). With Lv 80 full, RANK UP TO DECRYPTOR (in RECORDS → UNLOCKS, four presses) starts you again at Lv 0 one rank higher, and everything locks again to be unlocked by level once more. The one thing kept for good: DECRYPTOR N keeps N exploit slots (up to 6) from Lv 0, and the slots still to earn take the table's earliest slot levels (Lv 1, 6, 14 ...). A theme, font, track or difficulty picked but locked again falls back to the default until it reopens.

Exploit slots (loadout). Only exploits equipped in a slot are awarded. A new unlock drops into a free slot by itself; tap an exploit card to remove or equip it. Exploits to keep (Progress.isOwned / buyToOwn): the first three (RNG, BITFLIP, BUFFER OVERFLOW; FREE_EXPLOITS) are yours to equip as soon as they unlock; from TROJAN on, an unlocked exploit is bought once with resources (four times its one-game price in resources, no KEYS; BLACK BOX the exploit 40 CRYPTO + 8 ROOTKITS; always full price: no WEEKEND or FLASH SALE, HIGH DEMAND or YOUR DEAL, only a HOLIDAY's sale, and the rank's rise) and is then yours until the next RANK UP, which gives the bought ones up (its warnings say so: BOUGHT EXPLOITS ARE LOST). The EXPLOITS list splits its tiers with a ----- line (one section: ===== lines split sections). Its EXPLOITS card shows the price as have / cost (red where short); a first tap lights it, a second buys it (into a free slot when the loadout can change); short, what's short pulses red and the card's title says NOT ENOUGH. Its UNLOCKED notice adds // BUY IT IN EXPLOITS. FULL ACCESS (and the dev page's UNLOCK EVERYTHING) owns them all while it lasts. Saves from before this kept what they could already use: every exploit their level had reached or that was equipped (ownedSeed, OWN_SEED). The BLACK MARKET, EXPLOITS and BLACK BOXES still deal in any unlocked exploit (or any at all, a box), owned or not: a one-off taste. Under the EXPLOITS title the loadout is a row of six boxes, 8px apart and centered, each as the game's slot buttons: the equipped exploits fill them left to right, lit; an empty one is a dashed frame; one not open yet shows its padlock and the level it opens at (RANK for one a DECRYPTOR rank adds); in DAILY, its five; locked for the session, the filled ones dim a little. A loadout slot unlocking says UNLOCKED // LOADOUT SLOT n, and RECORDS lists LOADOUT SLOTS. No PAUSE shows in the corner while a card (the STORE, RULES & RECORDS, EXPLOITS, SETTINGS) is open over a game. The loadout is locked during a session: change it before the first drop or after the game ends. The daily games always use the five standard exploits, so they're the same for everyone.

Fonts (SETTINGS → FONT): COURIER is the default; SHARE TECH MONO, PRESS START, BITCOUNT, BYTESIZED and ORBITRON (Matt McInerney's wide geometric capitals, bold for the numbers) unlock by level. Each has an achievement for playing a full session in it (TECH SUPPORT, INSERT COIN, BIT BY BIT, BITE-SIZED, IN ORBIT). The font changes all the game's text (the particles and the dev page too) but never the layout: every button and display keeps the size and place it has in Courier. The fonts are bundled in assets/fonts/ and set up by js/fonts.js, which measures the device's own Courier (Courier New, Liberation Mono, Droid Sans Mono... it varies) and scales each font so its capitals are the same height, sitting in the same place in a line as tall as Courier's (every line of text uses Courier's line height). The buttons sized by their label are measured in Courier and locked to that size (lockButtons in js/script.js), and so are the notes and descriptions above buttons. A label or note too wide for its space in a wider font (PRESS START, ORBITRON) closes up its letter spacing, then shrinks, until it fits. The FONT and THEME notes keep room for their longest text, so picking one never moves what's below.

Tracks 12-15 are still to come (16 is GENERATED). COLLECTOR, DJ and AUDIOPHILE need all 16 tracks, so they open up once the last one is made.

VS matches aren't sessions. The SESSIONS achievements, the "in one session" ones (SCORE, NO TOOLS, ZERO-DAY, SECOND WIND, CHAINED EXPLOITS, the full-session theme / font / track ones and the finish-on-a-score secrets) and RAGE QUIT count only the solo modes. VS has its own achievements: VS CPU (wins, levels, COUNTERSTRIKE, DDOS, FLAWLESS, and the hidden TILTED and AFK), VS BOTS (beat each bot, all of them, all of them on INSANE) and VS MODES AND SETTINGS (a win in each mode and all four, 10,000-point and 5,000-point wins, BANKRUPT, KNOCKOUT, BARE METAL, ARMS RACE, ZERO MERCY). Bits, chains, nibbles, layers and exploits run in VS still count toward everything else.

Daily streaks follow the dailies' own clock (UTC). DAILY DRIVER, STREAK and CENTURY show your current daily streak, not your best: each new set of dailies (at 00:00 UTC, the same moment everywhere) is a day, and the streak drops to 0 once a whole set passes with no Daily game played. DAILY SWEEP shows the current set's daily games (DECRYPT, PUZZLE, BLITZ and BREACH) and starts over when they change. (The LOGIN STREAK and the DAILY DROP go by your own date.) Achievements for a run in a row (SURGICAL, PICKPOCKET) show your best run so far. Unearned rows in RECORDS say which kind of count they show.

RULES & RECORDS (main menu and pause screen) opens a card with two tabs, RULES and RECORDS; EXPLOITS and STORE have buttons of their own beside it (main menu and pause screen), each opening the same card on its own, under its own title and with no tabs. RECORDS has level and DECRYPTOR rank, every unlock and achievement with a progress tracker, and lifetime stats (UNLOCKS / ACHIEVEMENTS / STATS / HISTORY; STATS includes KEYS EARNED and KEYS SPENT: earned less what's held and what infections took). Everything in RULES, RECORDS and NOTICES sits 8px apart (headings, paragraphs, ===== lines, groups, rows, stat lines, RECORDS' own tabs). HISTORY (Progress.logGame, history) lists the last 10 games, newest first (not PUZZLE or the tutorial; VS matches too): the game (mode and difficulty, or the daily, or VS and the bot), how it ended (TRACED, TIME'S UP, DONE, BREACHED, WON, LOST), when, its score, drops, time (from the first drop), best chain, the KEYS and resources it earned as chips and the patches it used, under a line of the average and the best. Each is also marked, unseen, as a real game or not (LEGIT: 20 drops or more, 45 seconds or more, no more than 40 drops a minute, and at least a bit decrypted for every 4 drops): only real ones count toward the STORE's prices for you (below), so bits thrown in fast to lose don't. New unlocks, level-ups and achievements pop up as they happen (achievements stay up about 5.5 seconds, like a console's, before crumbling; the rest about 2). Progress is saved in the browser (bytefall-progress).

STORE (js/store.js, the cart tab): two purchases, REMOVE ADS (no ads, nothing unlocked) and FULL ACCESS (everything that unlocks by level, and no ads), each with its price and BUY (OWNED once bought), and RESTORE PURCHASES for another device or a reinstall. For a REMOVE ADS owner, FULL ACCESS is the upgrade at the difference (UPGRADE, and a line saying so), so nobody pays more than FULL ACCESS's price. In the app's RELEASE edition they're Google Play's (js/billing.js, with MainActivity's PURCHASES): its prices, in the player's currency; its purchase sheet; what the account owns checked as the game opens, whenever the app comes back to the front, and with RESTORE PURCHASES (a refund takes it back; a pending payment unlocks once it's paid); each purchase acknowledged, or Google Play refunds it after 3 days. What Google Play last said is kept (bytefall-purchases, not erased by RESET PROGRESS) so an owner's game opens without a banner flashing up first. Everywhere else (the website, ByteFall Test) it's a preview: BUY and RESTORE say the store isn't open and charge nothing, at the preview prices ($1.99 REMOVE ADS, $4.99 FULL ACCESS, $2.99 the upgrade; set the same in Play Console). REMOVE ADS is offered only there, on its own BUY button: no link or button for it anywhere else. Buying either one earns INDIE SUPPORTER (THANK YOU group): a real purchase only, not the dev page's previews (UNLOCK EVERYTHING owns FULL ACCESS; OWN REMOVE ADS owns REMOVE ADS). PRE-REGISTERED, beside them, previews the pre-registration reward (DAY ONE), as DEV MODE does along with everything else.

ADS (js/ads.js, the Android app only): the free version's banner, from Google AdMob through the Capacitor plugin @capacitor-community/admob (pinned to 8.1.0). Never on the web, and never once REMOVE ADS or FULL ACCESS is owned. On launch it starts the ads SDK, shows Google's consent form where the law asks for one (the EU, the UK, Switzerland...), then puts an adaptive banner (the screen's width, its height to suit) at the TOP of the screen, well away from the drop buttons. Android draws it over the page, so its height, as it reports it, goes to the AD STRIP (setAdStrip in js/script.js, the same room the dev page's AD BANNER PREVIEW keeps), and the whole game fits below it; until a banner has loaded (or if one fails, tried again a minute later) the strip is 0, so there's never an empty gap. On Android 15 and later the ads plugin moves the banner down by the status bar's room (though the game hides the bars and the page already starts below that room), which put it over the title; MainActivity puts its top back level with the page's after every layout, so it sits in the strip. Buying either purchase takes the banner and the strip away at once. The banner is the app's own view over the page, so it outlives a reload (DEV MODE's switch reloads the page): a page with no ads always tells the app to take one down, whether it put it up or not (removeBanner), so none is left covering the top of the game. Where consent applies, SETTINGS gets an // ADS section with AD PRIVACY OPTIONS, to change the choice made (Google requires it there). While testing is on, SETTINGS also gets // TEST ADS: a line on what the ads are doing (started or not, the consent answer, a banner showing, or Google's error code and reason there's none, or off because a purchase or UNLOCK EVERYTHING counts as owned), to see on a phone why a banner isn't there; and a consent check that fails outright (an AdMob account or its privacy message still being set up) doesn't hold the test banner back. With testing: false a failed check holds the ads till it works. The IDs live in js/ads-config.js: ByteFall's own App ID, and for now Google's sample banner with testing: true, which only ever shows test ads. tools/setup-android.js writes the app ID from there into the Android manifest (the SDK won't start without it). For the release: put in ByteFall's banner ad unit ID from the AdMob console and set testing to false. (The ByteFall Viz app leaves the plugin out: includePlugins: [] in visualizer/capacitor.config.json.)

js/progress.js holds the stats, levels, unlocks and achievements; js/script.js reports each drop, decrypt, peel, byte, exploit and point to it.

Dev switches. The </> dev page has DEV MODE (everything unlocked, like owning Full Access, for this browser; the game shows a DEV badge, a label only, level with the corner buttons and behind the wanderers, while it's on), JUMP TO LV 80 and +10 LEVELS for testing DECRYPTOR ranks, slots and exploit unlocks (real progress: what they open stays open with DEV MODE off, till RESET PROGRESS). In DEV MODE, three quick taps on any exploit's name make it your next drop; switched off, everything not earned or bought locks again and the loadout keeps only what's yours. AD BANNER PREVIEW (off by default; tap to step through 50, 60 and 90px, or add ?adpreview=60 to the URL) holds a gray strip at the top of the screen (AD BANNER SPOT switches it to the bottom, or add ?adpos=bottom) where a phone's banner ad would go. The game's height leaves the strip out, so the card, start screen, menus and music player all fit beside it, the way they would with a real banner that resizes the page. When less than about 650px is left beside the strip (a 360×640 phone, say), the board is at its smallest and the drop buttons start to crowd it. BACKGROUND (PLAIN by default, or ?twinkle) switches what's behind the game card between the plain gradient and TWINKLE: the start screen's starlight twinkling across the whole screen. Both dev switches take effect as soon as you go back to the game, no reload needed.

App view on a phone

The game has one text size, set large enough to read on a phone (there's no TEXT SIZE setting): every piece of text has its own size written in, nothing scaled on top. BYTEFALL is one size in one place everywhere: the main menu, every game (VS too) and the PUZZLES card, where // PUZZLES sits under it as a game's mode line does (every one centered across the top, its capitals level with the middle of the corner buttons; the main menu's isn't scaled up with the menu on a bigger screen). In ZEN, and VS with LAYERS: OFF, ENCRYPT IN keeps its place at full brightness, its count a - (no ===== under it). The main menu holds still: its title is one line at the top (BYTEFALL // DECRYPTION TERMINAL, 8px under the screen's top edge; just BYTEFALL where the whole line won't fit), with ← in the top left corner back to the title screen, then the level, the resources and the six modes; the mode's panel is only as tall as what the mode puts in it, PLAY 8px under its last piece and the rows under the panel right after, and what the mode shows in it (its description, DAILY's cards, the options) scrolls inside it on a short screen, fading out at its foot while there's more. The wanderers' lane at the card's foot is one fixed height (192px), the same on the main menu and in every game, whatever else is on the card; the defrag backgrounds (the grid's card, the mode card, VS's setup) are a little see-through (92%), so the lane's trees show faintly behind them, and the HAUNTED FOREST's two big trees in front (drawn in the frame editor at half the bots' pixels, finer than the rest: one for each edge, their crowns arching in) stand on trunks that run down to the card's foot, inside its border (the card frames the scene), the bots passing behind them; (out of the game for now, to be revisited: HOLLOW_ON in visitors.js) about one forest in three, the HOLLOW stands between them, as big, a dead tree in the same finer pixels: a twisting trunk with a scowl carved into it, red pinpoints glowing deep in its eye hollows, a gaping mouth of splintered fangs you can see the fog through, clawed twigs, a long arm reaching out with hooked fingers and roots gripping the ground. The two edge trees never match: each is drawn for its own edge. The forest has a floor: a silhouetted ground along the lane's foot down to the card's edge, earth with grass tufts in front of the bots' feet, stones, fallen twigs and dead leaves, laid out afresh each time the forest comes. The big trees' canopies arch in over the lane toward the middle (the HOLLOW's both ways). October also brings the HEADLESS HORSEMAN (a black horse at a gallop, its cloaked rider holding up a flaming jack o' lantern; HAHAHA, and poked, every bot near it jumps) and ZOMBIE HORDES (three to seven, shuffling in, out of the trees in the forest, some clawing up out of the ground; now and then they all break into the THRILLER for four bars, on the music's beat, then shuffle on). THE OVERCAST (OCTOBER and NOVEMBER, now and then, and over the HAUNTED FOREST most of the time it stands): three layers of pixel cloud roll in across the game card's sky, the far one darkest and slowest, the near one lightest and patchiest, each in masses with lit tops and dark undersides, so you see them stack and how thick they are; the birds and bats fly at one of three depths among them (behind the middle layer, between, or in front) and now and then climb or dip a layer, flying in and out of the cloud. October's is purple-gray with lightning flickering inside it, lighting it from within; November's is plain gray. It lifts after a few minutes (over the forest, it stays). The game card's sky (the clouds, the overcast's and the fog's dark, the night, the moon's sky) is feathered at the top: it reaches 56px past the lane's top edge and fades out there, into the UI above.

WEATHER (js/weather.js): over the wanderers on the game card and the start screen, all year. Every few minutes a spell may come, from the time of year's and the time of day's, and the date gives each day a lean (a wet day, a dry one, a stormy one, a calm one: the same for everyone). WINTER (Dec-Feb): SNOW that settles on the floor, a BLIZZARD (sideways, a whiteout), SLEET, a crisp SUNNY day, the AURORA on clear nights. SPRING (Mar-May): DRIZZLE, RAIN (puddles that drops ring, the bots' umbrellas up), a THUNDERSTORM (bolts, flashes, the bots flinching at the thunder), a SUNSHOWER, WIND full of green leaves and blossom petals, HAIL that bounces (an "ow"), SUNNY, a misty morning (the fog). SUMMER (Jun-Aug): SUNNY (a heat haze, the bots puffing), THUNDERSTORMS, a SUNSHOWER, a WIND of green leaves, FIREFLIES in the evening, a METEOR SHOWER at night (the most in August). AUTUMN (Sep-Nov): WIND full of red and gold leaves (blown in along the whole height of the side, settling across the floor), DRIZZLE, RAIN, a THUNDERSTORM, HAIL, a foggy morning, SUNNY. After the rain, now and then, a RAINBOW (never in HALLOWEEN or the HAUNTED FOREST). And through the year: OVERCAST days (the clouds alone), FLURRIES (winter, autumn's first snow, a late one in spring), THUNDERSNOW (rare: lightning in the snow), DIAMOND DUST (a bitter winter morning: ice crystals glittering), POLLEN and DANDELION FLUFF (spring and summer; a bot sneezes), a HEATWAVE (glare, a heavy haze), a DUST STORM (summer: a brown sky, dust streaming, a tumbleweed), HEAT LIGHTNING (summer nights: far flickers in the clouds), SUNRISE and SUNSET (the sky pink or orange, a big low sun rising or sinking), and THE MOON on clear nights in its real phase for the player's date (lit on the right as it waxes, the left as it wanes, the rest faint; none at the new moon), now and then over the other night skies too; in September and October its full moon is the orange HARVEST MOON. October's own moons (the werewolf's, the blood moon) stay as they are. The game card's lane gets its clouds for the rain, the snow and the storms (dark for a storm, pale for snow). The wind (its leaves, its rain and snow, the dandelion fluff, the tumbleweed) always blows the way the clouds drift: a spell that comes with clouds sends them its way, and one that comes while clouds are up blows theirs. Achievements: STORM CHASER (a thunderstorm, a blizzard and hail) and STARGAZER (the aurora, a meteor shower and fireflies). The dev page's WEATHER brings it OFTEN, in a chosen season, or one kind to stay; the BOT SANDBOX has a button for each.

THE CYBERPUNK STREET (js/cyberstreet.js, the scene CYBER; the bot sandbox's only, for now: not one the game picks yet, only the sandbox's CYBERPUNK STREET buttons or ?scene=cyber where the file's loaded): a long street at night, about four cards long, seen close up: the shops about twice as tall as the bots, their details plain, and the city beyond showing through every opening (over the low roofs, down the alleys, through the big windows, cut out of the wall), panning slower (parallax). Always night, a neon haze for a sky, rain and storms suiting it. Far off, black MEGATOWERS (a few windows, light strips, masts with red lights blinking); then THE CITY: blocks with window grids, small neon words, HOLO BILLBOARDS playing (BYTEFALL, a counting bit, an eye looking about, a beat, scrolling words; scanlined, glitching now and then) and an elevated line on pillars, a lit train along it now and then. THE STREET, lot by lot: a SHOP lit inside (its panes, shelves, posters, a glass door, OPEN in the window, a neon word over it: RAMEN, SOBA, ARCADE, DECRYPT ...), a SHUTTERED shop (lanterns along its awning lighting the shutter, a neon sign of glyphs, a ladder of neon rungs up the wall), the METRO (its big sign, the line's glyphs, a live clock, arrows, doors of lit mesh), a KIOSK wall (a terminal's radar screen, a ticket booth lit inside with its menu, a tall neon tube, pipes, a junction box), a wall with a big WINDOW the city shows through (cables hanging inside, a neon sign on the glass), a FOOD STALL (striped canopy, a string of bulbs, the pot steaming, its menu lit), LOW buildings (railings, a big rooftop sign on legs) and ALLEYS (left open: the city down them, a lit door far in, a dumpster, boxes, a sign on a bracket, cables across). Above the shops, a style a building: windows (someone at one now and then), slatted blinds lit from inside, balconies (plants, washing), an industrial face of vents; AC units, fire escapes, drain pipes, neon banners of glyphs (neon, or a lightbox), cables and lanterns strung from roof to roof; tanks, dishes and antennas on the roofs. A few signs are faulty and flicker. The sidewalk is wet, the shops' light and the signs' colors spilled in it, puddles; in front, bollards, grates (steam rising), bags, a cone. THE PAN: every minute or two the view drifts along the street, left or right as far as it goes, slowly (about 7px a second, easing in and out): the street and everyone on it pan with it, the bots carried along (one carried off the card walks on off it; wanderers.js's shift), the city at half the speed and the towers at a fifth. FOUR STREETS, one each visit (the sandbox's VIEW picks): MARKET STREET (all of the above, and an ARCADE: ARCADE in big neon, bulbs along its fascia, rows of cabinets in the dark, their marquees lit and their screens playing, a claw machine; a CLINIC: a green cross, a cold-lit window, an x-ray of a hand on a light box, the chair under its lamp; VENDING machines in a row, a capsule-toy machine; a NOODLE bar: its cloth curtain over the door, a glyph on each flap, the cook behind the counter, bowls steaming, stools, red lanterns), UNDER THE TRACKS (a viaduct right over the street on concrete pillars, graffiti and posters on them, sodium lamps under its deck, water dripping off it, its train thundering along on top, sparks off the pantographs; in its arches noodle bars, vending machines, chain-link GATES with barbed wire, a hazard sign and a scooter behind, a BARREL FIRE with embers rising and a robot warming itself, shutters, stalls), NIGHT MARKET (stall after stall under lower roofs, strings of lanterns everywhere overhead, cloth banners off them, a bigger crowd, vendors pushing carts) and CORPORATE PLAZA (glass towers, their lobbies lit cold: the company's name over the door, its mark on the back wall, turnstiles, a guard mech; a HOLO column between glowing planters, a koi turning in its beam; a VIDEO WALL a building high; polished tiles with light strips in them). The street is laid out in bot pixels, the same at any RES, each building's details from its own seed, and drawn at the RES (so the close-up can draw any spot of it again, finer, exactly as it stands). , behind the bots, at the bots' own pixel size and taller than them, dark (the four CPUs stay the ones you see), their eyes and lights glowing: HOODED figures in long coats, one under a neon UMBRELLA, chrome ROBOTS (a red light on the antenna), tall ANDROIDS (an LED strip down the coat), hovering DROIDS, DRONES flying over with parcels, CYBORGS (a red implant for an eye, a metal arm), security MECHS (big, slow, a red visor), COURIERS on hover bikes (fast, a light trail), VENDORS pushing steaming carts, stray CATS (eyes shining; they sit a while); each street its own mix. They come in, cross, now and then stop at a window, a stall or the metro a while, and go. Flying cars cross between the towers. (weather.js's, its real phase) is drawn behind the towers, a haze round it; the clouds, a storm's dark and flashes and October's moons sit behind them too; no stars over the city's glow. : only what a city's night has comes while it's up (rain, drizzle, storms, heat lightning, overcast, fog, snow, flurries, sleet, a clear night with the moon; ); anything else already out clears when it arrives, and nothing else starts, the season's or a button's. No rainbow (always night). stands in neon on a far tower's roof, on its scaffold (BYTE in the game's green, FALL in its amber; a faulty tube, now and then), the tallest one about the middle of the street, so it's in sight most of the time. : the street's pixels are a half or a third of a bot's (RES: 2x on a plain screen, 3x on a sharp one, where a third is still a whole pixel of the screen; the sandbox's RES buttons pick 2x, 3x or 4x), its parts measured in bot pixels so they stand as tall, the finer pixels spent on detail: window frames, sills and glints, brickwork or panel seams, the goods on the shelves, hanging lamps, a scalloped canopy, ribbed lanterns, neon tubes with a hot white core. The crowd is scaled up the pixel artist's way (Scale2x / Scale3x: smooth diagonals, still pixels), each pose drawn once and kept, a sheen along its top edges. : everything lit lights what's round it. Every sign, lightbox, lantern, lit window and door, screen, holo, barrel fire and billboard throws its color onto the walls, awnings, sills and wires near it, in stepped bands with the outermost dithered (pixel art's soft light); the viaduct's sodium lamps throw cones down to the street. It's worked out once when the street is built (a light map per layer, added onto the layer's own pixels only, a strip at a time) and costs nothing after. The crowd is lit by where it walks: the street's light along the sidewalk, a bot pixel at a time, washed over each figure. : the street is mirrored in the sidewalk (its front upside down from its foot, squeezed into the sidewalk's depth, rippling, fading, its lit signs brighter in it than its walls), pools of the lights lie on it under each (the lower the light, the brighter its pool), their colors streaking down it. In the close-up the whole street front is mirrored in the road too. : a 5x7 neon font for the big ones, each stroke a tube with an unbroken hot core (no more LED dots): shop names in framed lightboxes (the frame a neon tube too), the METRO, the companies' names, the rooftop signs, BYTEFALL up on its roof. : bundles of cables strung from wall to wall everywhere but the plaza, two to six together, each its own sag, some spanning a building (their own random: the rest of the street stands the same). (not ByteFall's: off unless the sandbox's PEOPLE turns them on; a start on a city's people for a game of its own): people in coats, each their own skin, hair, coat and trousers, one under a clear umbrella, one lit by the phone in their hands; they join the crowd's mix while on. : no cheer on the bots' faces while the street is up (the lane gets 'gloomy', wanderers.js): happy turns skeptic, love worried, laugh smug, no cheery emotes (^^, <3, haha), meetings drawn from a gloomy set (no grins), and EASY's resting smile shows as a flat look (style.css). : one passed close behind by a figure turns to look and reacts in a bubble (a mech: scared; a hooded one: wary; a courier zipping by: startled; a robot: beep?), looks up at a drone or a train going over (the viaduct's, right overhead: scared), at a sign over it sputtering out, flinches at a grate's steam under it, warms itself at a barrel fire, eyes a lit shop window it's stopped at; one bot at a time, each a while before it notices anything again ( events). : every two to four minutes (not while panning; the sandbox's ▶ CLOSE-UP for one now, which brings a CPU in first if none is on the street), the view cuts in on one of the CPUs, anime style, for about six seconds, : the street right there drawn again at four times the bot's pixels, each layer from where it shows behind the bot at its own parallax (the shop or the arch behind it, its signs lit, the city through the gaps, darker as it's farther), the wet sidewalk, then a curb and the road in front, the signs' and shops' colors streaking down its wet, what's in front at the curb; whoever's walking by there walking by, four times finer too (no one about? someone comes past behind it). The bot under half the frame tall and drawn at four times its pixels (its own art as it is that moment, read off its page element: mood, face, headphones and all; Scale2x twice), lit by the nearest sign: a neon rim on the sign's side and its glow past the edge, shadow and a dither on the other, lighter up top and darker to its feet, the night's blue in it, rain's sheen on top, a shine in each eye, its face glowing; its reflection rippling in the wet. Rain streaking past (or snow drifting, by the weather; lightning in a storm), a stepped vignette, letterbox bars, a white flash at the cut, a slow push in, a breath. Then the cut back. In the game card it fills the whole scene; on the start screen, the lower part, under START. What's still is drawn once, the whole street, and slid; only what changes is redrawn (a flicker redraws that sign, and only the part of its neighbors under it, on its own layer). REDUCED EFFECTS: no flicker, no steam or embers or drips, no push in or breath, nothing falling in the close-up. Meant to become the lane's usual place, the other scenes the occasional ones, once it's ready.

SCENES (js/scenes.js): now and then (a few times an hour, 10-20 minutes each) the lane becomes a place, by the time of year: MEADOW (spring, summer), BEACH (summer: the sea's waves moving, a parasol), CITY (any time: a skyline, more windows lit at night, a sidewalk, a hydrant), WOODLAND (spring to autumn: the trees and the path's litter in the season's colors), SNOWFIELD (winter), DESERT (summer), FARM (autumn: a red barn, pumpkins) and LAKE (spring to autumn: a woodsy lake, reeds and lily pads). The LAKE and the BEACH have a pier: now and then a bot walks out on it (up its steps), casts, and waits; the bobber bobs, nibbles and goes under, and it reels in a fish (held up, pleased, thrown back), now and then a golden one (heart eyes), or an old boot (put out), and 1 time in 10 a RESOURCE off the bottom, kept and yours (BUGS, CACHE, CRYPTO, ROOTKITS, or rarest, a MASTER KEY; the notice line says which); then it casts again or heads back. TAP THE BOBBER and the fish is gone: the bot's upset (hey! my fish!). BITS OF LIFE in each place, behind the bots: at the LAKE a fish jumping (rings where it goes in), rings on the still water, a duck paddling across, a dragonfly darting over the reeds; at the BEACH a fish jumping, gulls gliding over, a crab scuttling along the sand; and a bug here and there: butterflies and a bee over the MEADOW, a beetle or a ladybug on the WOODLAND, FARM and DESERT ground, a moth in the woods at night, pigeons pecking along the CITY's sidewalk (the day ones keep in at night). And NEAR CRITTERS, bigger, close by on the bots' own floor (in front of them): a frog hopping along the lake's shore, a crab on the beach, butterflies, a bee and a rabbit in the meadow, a squirrel in the woods, a chicken on the farm, a lizard in the desert, a pigeon in the city, a rabbit in the snow. The bots notice one as it passes and it sways their mood: a butterfly a heart, the rabbit an "aww", a frog a curious "ribbit?", a crab a start (now and then a pinch: ow!), the bee worries them (BUNKER: EEK; GLITCH laughs), GRIFTER eyes the pigeon; each nudges their temper and fun. Behind each scene, its SKY: the time of day's (a night navy, a dawn's peach, a day's blue, a dusk's orange and violet), turned by the weather (gray in cloud and rain, dark in a storm, pale in the snow, brown in a dust storm, warm in a heatwave), crossfading as it changes and fading out up top into the card; on the start screen the sun and moon come down into it. Poke the bot and it shushes you. Achievements: GONE FISHING, THE ONE THAT GOT AWAY. No numbered BITs are pushed in while the pier's out (one would stand in front of the bot fishing off it). Each is drawn at three depths, never all in front: a far layer behind everything, the ground behind the bots' feet, and a few details in front of them. The weather leans to suit it (a beach's sunsets and storms, a city's rain, a snowfield's snow; never snow on the beach), and half the time it brings a spell of its own. Not with the fog or October's HAUNTED FOREST. The dev page's SCENE brings them OFTEN or keeps one; the BOT SANDBOX has a button for each.

A button's tick (and buzz) comes on a successful tap, released on it, not on a touch that slides off. The buttons are one size in every mode and font, their words centered; a word that won't fit on a button shrinks, never under 10px. Through the game the font never changes a button's size or moves the HUD, the board or its buttons.

• Add to Home Screen (Chrome's menu on Android, Share on iPhone) installs ByteFall with its own icon, and it opens full screen like an app, without browser bars. manifest.webmanifest and assets/icons/ (the icon's source is icons/icon.svg) set that up.

Daily bonus, vibration and resetting

• Daily bonus: each day (local date), one free exploit (claimed in the STORE's DAILY DROP) waits loaded in the exploit button. The new day's drop (and the LOGIN STREAK's count) comes when the game opens, or when it's brought back from the background after the date has turned, or within a minute of midnight while it's open; a claimed one waiting in a game under way stays for that game. Arming it makes one of the first five exploits (RNG, BITFLIP, BUFFER OVERFLOW, TROJAN, WORM VIRUS) your next drop, even if you haven't unlocked it yet, so new players get to try them. It doesn't stack if unused, and it's hidden in DAILY and PUZZLE so those stay equal for everyone. Its notice (like every notification but achievements) waits until you're past the start screen.
• Vibration: on devices that support it (Android), drops, decrypts, exploits, new layers and game over give a short buzz. VIBRATION in settings turns it off; the option only appears where it works.
• Reset progress: at the bottom of RECORDS → STATS, with a two-press confirm. It clears stats, unlocks, achievements, puzzles, best scores, the LOGIN STREAK and the DAILY DROP (today's comes back to claim); settings stay.
• A save that can't be read (cut off mid-write, say) starts the game fresh, but it's kept aside first as bytefall-progress-unreadable, so nothing more can overwrite it and it can still be recovered by hand.

Full Access

The Android app is free with a banner ad, plus two purchases (the STORE): REMOVE ADS, and Full Access: no ads, and every unlock straight away. Nothing needs it; everything can also be earned. js/unlocks.js holds that check (never owned on the website; the RELEASE edition's set from Google Play, js/billing.js). Add ?unlockall to the URL to preview everything unlocked.

TEST PURCHASES (app builds with test ads only, SETTINGS): in ByteFall Test (no Google Play billing) BUY in the STORE pretends: owned at once, nothing charged, the STORE's preview line saying so, kept across launches (bytefall-test-purchases), and the UPGRADE offered after REMOVE ADS as it would be; RESET TEST PURCHASES takes them back, ads and all. In the Google Play build BUY is Google Play's own sheet (a license tester's test card) and RESET uses the purchases up so they can be bought again (see Releasing to Google Play).

Playing

The game fills the screen with no card or frame around it (the phone's own edges are its frame): everything sits 8px in from the screen's edges, the room going to the board, the HUD and the main menu's panels (the DAILY cards included). VS sits its board a little narrower when the screen's height is what limits it. The title screen and the music player have no card either. (The game in a bordered card, as it was before: commit 318ba34.)

Open bytefall.html in a browser (or index.html, the landing page). Tap a drop button (under the grid by default; lettered A to G left to right, A to H on Hard, colName, so a column is never read as a bit's number: everywhere a column is named it's by its letter, the tutorial, PIVOT, ADWARE and the DAILY PUZZLE's hints too), or press 1-7 (1-8 on Hard) on a keyboard, to drop the current bit shown in the HUD. Or touch the grid itself: touch (or click) and hold, and the bit appears in the top row over that column, following your thumb (or the cursor) from column to column; let go to drop it there (let go well off the grid to call it off). A quick tap on a column drops straight in. PIVOT's choice of side shows as arrows in the top row too, and the button over the aimed column lights up. Both ways always work. RESTART (two taps) is on the pause screen; there's no corner button for it.

The HUD (not VS): BEST over SCORE on the left, CURRENT large in the middle (on Easy, NEXT in a short panel under it, its bit in full color as CURRENT's; TIME or BITS LEFT under it in the timed and counted modes), ENCRYPT IN over CHAIN on the right (CHAIN the whole column in ZEN). The four small boxes are one size (two equal rows): each its title 4px from its top edge, its height that title plus 8px, the 16px value and 8px; the value itself centered between the box's top and bottom edges, and across, by its digits (trimmed to their capitals, so what shows is centered, not the font's line box). CURRENT is as tall as the two beside it, its title 4px from its top and its bit (its own 42px) centered the same way, never closer than 2px under its title (over NEXT or TIME the box is shorter, and the bit sits that 2px under it; NEXT and TIME's words and value are trimmed to their capitals, so they center in their strip by what shows). SCORE's story meter (2px tall, 3px up from its foot) and ENCRYPT IN's ===== sit in the band under their values and take no room of their own (the ===== centered in it, between the foot of its count's digits and the box's bottom edge, as CHAIN's floaters are; --val-foot). It's one shape on every phone: laid out at 368px (HUD_DESIGN_W, the S23 Ultra's) and zoomed to the grid card's width (script.js's zoomHud, from fitBoard, which works the board's size out twice, since the HUD's height follows the board's width), so its boxes, CURRENT and their words keep their proportions on a narrow phone (a Fold's cover screen) as on a wide one, and the grid under it the same; a screen wider than the game needs (a Fold open) keeps the game at its width, centered, empty either side. VS lays out its own squares.

THE CHAIN METER, a streak: a 5-segment bar up each side of the grid, exactly as tall as the grid's squares (the top row's top to the bottom of row 1), set off from the grid by the same 3px gap as between its squares (both ==== lines run on under it). Every link of every chain lights one, from the bottom; fill it and an exploit is earned, and the meter starts over, empty. How it keeps its charge by level: EASY and NORMAL carry it from drop to drop (as long as a drop clears a bit), a drop that decrypts nothing taking one segment off on EASY and emptying it on NORMAL; HARD and INSANE empty it as soon as each chain ends, so the 5 links have to come in one chain. Only one exploit at a time: while one waits (earned, the daily free one, or armed) chains don't charge the meter at all; it waits empty, pulsing amber, until the exploit is used. ZEN and the tutorial play NORMAL's rules, BLITZ its difficulty's, VS the CPU's level's; the CPU's exploits come from the same streak on the same rules, one at a time. While an exploit is ready, the bars pulse amber (and the exploit button pulses), and an earned one also shows EXPLOIT READY // its name on the notice line for a few seconds. ENCRYPT IN has a ===== under its count (the layer it counts down to, as a bit is [n]), flashing with the line under the board when the next drop brings one; both at full brightness in the terminal color the rest of the time.

The tutorial opens on a welcome (BEGIN), then short steps, every card listed in TUTORIAL.md (the heading is just // TUTORIAL: no card number or count, so the count isn't what a player watches); on a step that asks for a tap, the screen dims a little but for what to tap and the banner (a 0.25s fade, its openings measured from the dim's own corner, so the ad banner never shifts them); a step can take its drop in more than one column (column D or G; the layer peels: C, D or E). A card can also put things in focus (focus): the same dim, cut open around each (the bottom row, the two PATCH SLOTS or EXPLOIT SLOTS, a menu tab, the LV box, the loadout, YOUR RESOURCES, PRICES TODAY, the ENCRYPTION STRENGTH line and the SCORE bar, the last two framed 8px out: roomy); SETTINGS' card scrolls smoothly to DISPLAY (scroll). The drop buttons are never faded in the tutorial (a tap the card doesn't want gets -_-). The last two cards are on the main menu (home: a fresh CLASSIC behind it, PATCHES and EXPLOITS in focus, no BACK out of it), and the last one's MAIN MENU earns HELLO, WORLD (finish the tutorial; +10 KEYS). The chain meter keeps its charge from the chain lesson through the WORM VIRUS.

THE EXPLOIT BUTTON: under the grid in its own row, below the drop buttons with a gap between (it's not one of them), a square the size of a grid square with the exploit's symbol in the middle (the daily free exploit just loaded in it, unmarked). With nothing held, tapping it just buzzes: the EXPLOITS card (the loadout) opens only from its EXPLOITS button. The HUD's labels (SCORE ... CURRENT) are brighter.

The gear/speaker icon in the corner opens the settings: sound and music on or off, whether the drop buttons sit under or above the grid, the color theme and the playlist.

Themes (picked from the swatch grid in settings; a locked theme or font shows its unlock level in its corner, LV 12, as the playlist's tracks do; the page fades to the new one over 1 second, 1.25 into or out of PAPER):

Theme	Bits	Layers	Cracks & exploits	Trace
TERMINAL (default)	green	gray	amber	red
CIPHER	cyan	magenta	yellow	orange-red
AMBER CRT	amber (a yellow amber)	gray	cyan	red
MONOCHROME	light gray	striped gray	white	white
ANAGLYPH	off-white with red/cyan 3D fringes	red	cyan	red
SYNTHWAVE	pink	purple	orange	cyan
DOT MATRIX	olive green	dark green	pale green	red
PAPER	near-black ink on paper	gray	dark amber (gold)	red
GLYPH	shapes on blueprint blue	slate	amber	red
SPECTRUM	each bit cycles the rainbow on its own	gray (still)	near-white (still)	cycles
ZERO DAY (DAY ONE)	gold on obsidian	champagne	pale gold	red
HOLO FOIL (DAY ONE)	foil: teal, violet, gold, a white flash	pearl-edged slate	white	rose red
BLUEPRINT (DAY ONE)	white outlines, cyan numbers on blueprint blue	hatched	marker yellow	red
FIRST LIGHT (DAY ONE)	rose gold on deep indigo	lavender	sun yellow	rose red
SEASONAL	the time of year's: OCTOBER pumpkin orange, NOVEMBER gold, December evergreen, FROST (Jan 7 – Feb) ice blue, VALENTINE'S (Feb 7 – 14) rose pink, SPRING (Mar – May) fresh green, SUMMER (Jun – Aug) sea aqua, SEPTEMBER school-bus yellow	each season's	OCTOBER purple, NOVEMBER rust, December red, FROST silver, VALENTINE'S rose red, SPRING blossom pink, SUMMER sunshine, SEPTEMBER apple red	its season's

GLYPH draws each bit as a shape with one corner per point of its number (1 is a teardrop pointing up, 2 a lens, 3 a triangle... 8 an octagon, and 9, CHECKSUM's only, a nonagon), with a small number in the corner. SPECTRUM gives every bit its own random hue speed, direction and phase, slowly hue-rotates the rest of the page (the title screen too), starting from a random point in its cycle on every launch and every switch to it (not always the palette's own red), and turns the background grid into dimmed rainbow blocks; under reduced motion it holds still, on a random hue. SEASONAL (free, the full-width button under the other themes) follows the calendar: in OCTOBER the title flickers now and then like a failing light; in DECEMBER (to Jan 6) the background's blocks are bulbs of every filament color, twinkling, the board catches the lights' warm glow. FROST's ICE (January 7 through February, js/lights.js): no lights; the same strips down both sides of the screen hold ice instead, a pale crust along the edge, thicker toward the corners where frost gathers, pixel frost ferns branching in off it and a few glints catching the light in turn (hidden on EFFECTS: REDUCED, as the lights are). THE SEASON'S LIGHTS: strings of old filament bulbs in fine pixel art (finer than the bots', each turned its own way: hanging, leaning, sideways, a few pointing up off the wire) run down both sides of the screen, top to bottom, a bulb at either end (js/lights.js builds them to the screen's height), the wire in the screen's 8px margin and every bulb turned in toward the middle, so none is cut off at the edge; over everything, but never in the way of a tap (their glows end at the screen's edges, so the page never scrolls for them), glowing and twinkling in turn, the CHAIN METER's segments in their colors: December's C9s of every color, October's orange, purple and green with jack o' lanterns and candy corn among them, Valentine's pinks, red and white with hearts. EFFECTS: REDUCED takes them (and December's warm glow) away.

DAY ONE (the PRE-REGISTRATION REWARD: Google Play's day_one, billing.js; Unlocks.hasDayOne): four themes only those who pre-registered have, listed in SETTINGS above SEASONAL under their own head, DAY ONE // PRE-REGISTRATION REWARD (and their notes saying so); for everyone else they aren't there at all, and CHAMELEON counts without them. ZERO DAY: the bits cast in gold, lit from above; every 12 seconds a glint of gold light sweeps the screen. HOLO FOIL: the bits' colors run across the board together as light over a foil card, each that far along one cycle by where it sits (foilBit, a diagonal; a white flash as it passes). BLUEPRINT: the bits drawn in white with a tick at each side's middle, hatched layers, a drafting grid behind the board. FIRST LIGHT: dawn at the top of the screen, breathing slowly. REDUCED EFFECTS and reduce motion still the glint and the dawn (the foil holds still under reduce motion). Those who have it also get the DAY ONE badge, a small gold tag by RECORDS' title, and, the first time it comes, DAY ONE // THANK YOU FOR PRE-REGISTERING on the notice line (kept in NOTICES, saying where the themes are). Google Play taking it back hides them again; the theme picked comes back if it returns.

Every color in css/style.css is a named role in :root; a theme is a [data-theme="…"] block that overrides those values, plus an entry in THEMES in js/script.js and in the small theme scripts in bytefall.html's and arcade.html's heads. All but TERMINAL and the DAY ONE four are unlocked by playing (see below).

The corners. RESTART is the arrows icon in the game card's lower-left corner, grayed out until a session's first bit drops (QUIT in VS); the exploit button is in the lower-right.

The layer line. A ==== line under every board (and the CPU's) marks where encryption layers rise from; it flashes amber when the next drop brings one.

No scrolling. On every screen (phones, the app and desktop) the footer sits inside SETTINGS and the game card fills the screen height, so the game page never scrolls. The footer (it stays in the live app) has the copyright, then the build number (the page's own version), when it was last updated and the commit. The header sits at the top of the card, level with the icons; the board stays centered.

RESTART and the difficulty buttons ask for a second press mid-run (RESTART turns red, like the other confirms; the text buttons read CONFIRM?; either cancels itself after a few seconds), then the board melts down like a traced run before the new one starts. Once a run is over, or before the first drop, they act straight away.

Font sizes

One scale for every menu card (RULES & RECORDS, EXPLOITS, the STORE, SETTINGS, the info cards); the full rules head css/style.css, so they're the first thing seen when changing styles. In short: 17px card titles and item names, 15.5px section heads and banners, 14.5px body text and the ===== lines, 13px notes and sub-heads, 12px buttons, 11.5px small tags, 10.5px HUD labels, 9px the floor. Sections are parted by ===== lines, never dashes.

Files

bytefall.html (and index.html, arcade.html, byterrium.html, dev-tools/*.html, arena/index.html) load their CSS and JS with a ?v=N tag (bytefall.html's is the build number the Android builds read). Bump N on all of those links whenever any of those files change, so browsers don't pair a fresh page with a cached older script (GitHub Pages lets browsers cache for 10 minutes).

• bytefall.html — page structure, HUD, rules and exploits panels
• css/style.css — terminal/hacker visual theme
• js/script.js — game state, rendering, chain resolution and exploits
• js/unlocks.js — the Full Access check (never owned on the website; ?unlockall previews it)
• assets/fonts/ — the unlockable fonts, Share Tech Mono (Carrois Type Design), Press Start 2P (CodeMan38), Bitcount Single (Petr van Blokland) and Bytesized (Baltdev), from Google Fonts, with their SIL Open Font License files
• js/cpu.js — VS CPU: the computer opponent (a copy of the board rules with no animation, and a player that tries every column)
• js/progress.js — lifetime stats, earnable unlocks and achievements
• docs/STORIES.md — STORY's stories as the game has them now (the preliminary version); docs/STORY-V2.md — GHOSTS, the STORY rework draft for review (an informant's IMs, a black market and threatening calls introducing the tools; jobs played as PUZZLE, BLITZ, BREACH, DECRYPT and VS); docs/STORY-PROMPT.md — the brief for writing GHOSTS with other assistants, and notes for a branching story
• docs/achievements.csv — every achievement grouped by what it's about (category, name, description, goal, and whether it's standard, hidden or impossible)
• manifest.webmanifest, assets/icons/ — the home-screen app view and icons
• js/data/puzzles.js — the PUZZLE boards, generated and verified by brute force (1-3 solutions each, none solvable in fewer drops)
• js/data/daily-puzzles.js — the DAILY PUZZLE boards, one per UTC day for about three years (then they loop), generated and verified the same way (1-3 solutions each)
• js/fx.js — particle overlay: cleared cells dissolve into pixel fragments and drifting hex/binary glyphs (skipped under reduced motion). The game never waits on a burst: its pieces hold the bits' place until they fly, while the board collapses, the chain carries on and the next drop is open (a single link frees it in about a third of a second, a second or so before)
• js/viz.js — the shared music visualizer (LED bars or auto-gained oscilloscope wave with a CRT trail) used by the playlist and the dev page; the chosen style is remembered for both
• js/grid-bg.js — the dim "defragmenting" micro-grid animated behind the board (performance: only the blocks whose brightness changed are redrawn each frame, in batches by shade, with the theme's color read once per theme change; the board's and HUD boxes' rest under the main menu; static when the OS asks for reduced motion)

Stereo

Every track is mixed in stereo. Drums, bass and the lead stay centered; the rest is placed the way each style would be mixed:

• 01 BYTEFALL THEME, 02 SLEEP MODE: pads and detuned voices spread left and right, arps alternate sides, hats sit right, the tension saw / alarm left, echoes come back from the right; SLEEP MODE's guitars are double-tracked hard left and right.
• 03 BRUTE FORCE (an NES stereo mix): the arpeggio alternates sides (its 32nd-note doubling on the other), hats right, the octave double left, the boss duet right, the low-battery beep left.
• 04 DEEP WEB: the drone's detuned pairs split wide, bleeps land on either side with their echo from the right, hats right and shaker left, plucks alternate, dub stabs lean left, the modem left.
• 05 ZERO DAY: the reese's two saws a little apart (the sub centered), the pad split wide, hats right, the rave stab's square left and saw right, the siren sweeping left to right and back.
• 06 SYSTEM RESTORE: the piano spread low-left to high-right, the vinyl on both sides, hats right, the flute just right of center, the stutter ping-ponging, the strings split wide, the error chime's two notes either side.
• 07 NIGHT DRIVE (a wide 80s mix): the pad's three saws left, center and right, the arpeggio alternating with a ping-pong echo (each note's echo starts on the other side), hats right, tambourine left, the tom fill rolling left to right, brass and choir spread out, a wide crash, the riser drifting across.
• 08 STANDBY MODE (a combo on a small stage): guitar left, harmony sax right, guiro and shaker right, tambourine left, the strings spread out, in a stereo room.
• 09 CORE DUMP: the guitars double-tracked through two amps, hard left and right; ride right, china left; the harmonies either side, the sweeps alternating.
• 10 HANDSHAKE (Game Boy style): pulse 2 left, the lead's echo right, hats and the fake-chord arps right, the low-HP alarm's two tones trading sides.

Panned sounds get +3 dB ahead of the panner (it halves a mono sound's power), so each track kept its loudness (within about 0.3 dB of its mono mix).

Rules

RULES & RECORDS → RULES: a folder for each section, its title alone (no wall of text): THE BASICS (drop, decrypt), SCORING, LAYERS AND THE LINE, EXPLOITS (the chain meter and the loadout), THE BOTTOM ROW (side slots, the BLACK MARKET, patch slots, BLACK BOXES, infected bits), STORY, DIFFICULTY, RESOURCES AND LEVELS, THE STORE, RULES & RECORDS and SETTINGS; the TUTORIAL button beside the title. A tap opens the section's page by itself (showRulesSec; ← ALL RULES back, RULES opening on the folders again; a refresh keeps the page): what it says, and beside its title the section's own TUTORIAL where it has one (every section but STORY, DIFFICULTY and RESOURCES AND LEVELS): a short lesson on that section only (tutorial.js's LESSONS), its last card's RULES (or EXIT) back on the page. STORY says COMING SOON and nothing else for now, its rules kept under it in bytefall.html (.rules-later, hidden) for when it opens.

Tutorial

MAIN MENU → TUTORIAL, or RULES → TUTORIAL (beside the title), starts a guided lesson on set boards with set bits (js/tutorial.js). BOT narrates it: its face sits in the banner's corner, and each line types out fast with a blip of square-wave "voice" every other letter (Animalese-style, following SOUND), pausing at punctuation; a tap on the text finishes the line, and the lesson never waits on the typing. BOT's mood follows along (happy at the welcome and the chain, worried at the ======== line, devious with the WORM VIRUS, -- at a wrong column). A banner over the board explains each rule and asks you to tap what it names; whatever it's talking about pulses, and only the lesson's drop column can be pressed (the others dim). Taps follow the card: one before BOT has finished talking shows the rest of the words at once and gets -- (the next does its job); once it's said, anything the card didn't ask for (PAUSE, other buttons, the menus) gets -_- and does nothing; EXIT always works. PAUSE (its button, Esc, P) only works on the card that asks for it. After each drop it says what happened and shows the points, a line a link, each part its own color: [2][5][2][5] 12+15+12+15 ×1 = 54 (the bits, what each is worth, the chain's multiplier, the result), NIBBLE bonuses and the total; the words and points 8px apart line to line. The steps: the terminal and its bits, CURRENT, a line across, a line down, scoring, SCORE, chains, a NIBBLE, CHAIN and the CHAIN METER, peeling a layer twice until it reveals its bit, the ======== line, ENCRYPT IN, an exploit (arm the WORM VIRUS waiting in the EXPLOIT button, then drop it on a tall column), the bottom row (its slots shown locked, then one as a BLACK MARKET with a TROJAN for sale and its pips), PAUSE (top right) and the pause screen, RULES & RECORDS (RULES, RECORDS on its UNLOCKS tab with the tabs, levels and RANK UP, NOTICES), ← BACK, EXPLOITS (the loadout, buying exploits), the STORE (resources, PRICES TODAY, then a card per section, each scrolled to and framed: the DAILY DROP, PATCHES, EXPLOITS, BLACK BOXES, SUPPORT THE GAME), SETTINGS (SOUND, then DISPLAY and EXTRAS scrolled to), RESUME, then on the main menu PATCHES and EXPLOITS. The TUTORIAL itself is only how the game is played (26 cards: the welcome, the terminal and bits through the WORM VIRUS, then MAIN MENU); everything from the bottom row on is in RULES' own lessons instead, each on its section's page: THE BASICS, SCORING, LAYERS AND THE LINE (the CHAIN METER set to 3 bars as it starts, meter, as the chain lesson leaves it), EXPLOITS (the WORM VIRUS, then PAUSE → EXPLOITS, the loadout), THE BOTTOM ROW, RULES & RECORDS, THE STORE (ending on the main menu's PATCHES and EXPLOITS) and SETTINGS, a lesson's first card on a clean board. STORY isn't in any (its own terminal intro explains it). Every card about a place opens it (its tab, its section at the top of its page). Over an open menu the banner moves to the bottom or middle of the screen; over the main menu it starts at the top of the EXPLOITS / STORE row and grows down. What a card points at is framed in one layer over everything (: nothing covers a frame), 4px out (8px for a roomy one), with the narration card's 6px corners, as the dim's openings have; measured from that layer's own corner, so an ad banner over the top (the page moved down under it) never puts them a banner's height off. Framed things whose frames would overlap or touch (a WORM's column of bits, two bits side by side, the EXPLOITS menu's cards) get one frame, the rectangle round them all (), and one opening in the dim the same. TUTORIAL.md lists every card, written by from the lesson as it plays. BACK (from step 2 on) redoes the step just played, or before a drop goes to the step before, putting the board, bits, score, chain and exploit back as they were. EXIT leaves at any point. It counts toward nothing (no XP, stats, achievements or best score). Notices (a poke's achievement, say) show on the notice line under BYTEFALL, clear of the banner.

Only what shows is drawn

Each screen gets the device to itself; what's under it is held in memory, not drawn or moved, and carries on from where it was when it shows again (nothing restarts):

• The MAIN MENU covers the game: the grid isn't drawn (render waits, renderStale) and the game's layout isn't worked out (fitBoard waits, boardStale) until PLAY closes the menu, once. Picking a mode (VS above all) no longer lays out a screen no one sees.
• RULES & RECORDS, EXPLOITS, the STORE and SETTINGS (body.panel-open) cover the menu, the game and the wanderers' lane: those aren't drawn, and the background starlight canvases (grid-bg.js) rest. The MUSIC PLAYER (body.player-open) covers the whole game card the same way.
• The wanderers (wanderers.js's suspended) hold where they stand under a card, the music player, the start screen or the screen saver (their steps and blinks paused too) and walk on after; only WANDERING BOTS: OFF clears them.
• Each background canvas runs only while it can be seen (the board's and HUD boxes' under the game, the menu panel's under the menu, the VS setup's while it's up, the start screen's while it's up; on the ARCADE's own page, arcade.html, its card's and its game's board's, and the menu's previews only on the cards on screen), and one with no size isn't touched at all.
• Lists: STORE and EXPLOITS items and RECORDS' rows scrolled out of sight hold their animations still (.off-view). The STORE's "short" pulses and its sign fade only (the glow held steady), which the graphics chip draws, instead of a glow redrawn every frame.
• The weather keeps its layer's size as it changes rather than measuring it every frame.

Startup

A fresh launch (the app or tab opened anew) opens on the START SCREEN (the studio, EMPTYFISHTANK PRESENTS, across the top; the copyright above the wanderers): a card filling the screen with the starlight twinkling across it, the BYTEFALL title in the middle and START below it, a neon sign (its tube's core near white, the theme's color glowing round it), as far under the tagline as the tagline is under the title (measured letter to letter, in every font, and placed before the first paint by a small script in bytefall.html, so it's never seen anywhere else first; js/start.js). On a launch the title plays an intro (and again each time BACK comes here from the main menu), one of five picked at random (never the same one twice running; ?intro=drop, bit, rain, decrypt or power picks one): DROP, the title falling from the top, gathering speed, and landing hard (a squash, a jolt, and an amber band under it bursting into pixels and binary dust); BIT, the title falling as a bit does on the board, a row at a time, a fading ghost of it left at each row it passes, landing with a bit's bump, a puff and a ghost swelling out from where it landed; RAIN, its letters falling one by one like bits down their columns, each landing in a puff; DECRYPT, scrambled glyphs locking into its letters one by one; POWER, an old CRT switching on, a bright line opening out into the title. Then the tagline types in behind a block cursor and START flickers on like a neon tube catching. LIVE (the live test app only, BYTEFALL_APP.live, where the game loads from the site and so is always the newest push; ?live shows it anywhere): "live" in neon script up in the start card's top right corner, under EMPTYFISHTANK PRESENTS and clear of the title, tilted like a sign in a bar's window: one hot-pink tube written out in joined-up letters with a cyan swoosh under it, no plate or frame, just the bent glass (dark till lit, then a near white core in its glow, a soft halo behind), its own colors whatever the theme. It flickers on with START as the intro ends, never quite in step: one of the two a beat behind the other (either first, 0.12 to 0.75s; now and then both at once), each unseen till its own flicker starts, the swoosh catching on its own beat. Lit, every 3 to 11 seconds a letter stutters as an old tube does (now and then two). Skipped, it's simply lit. The intro plays on a copy of the title laid over the real one (which never moves), and nothing of it shows before it plays. A tap, or a key, skips to the end; there's none on a refresh after START, coming back with BACK, or with REDUCED EFFECTS or the system's reduce motion on, and no sound (browsers play none before the first tap). A tap anywhere else lets the music begin (browsers need one) and leaves you on the screen. START (or Enter / Space) fades the start card's contents out, its border staying (the start card is laid exactly over the game card: the same size and place, on a phone or in a browser), and the MAIN MENU fades in inside the same border. The very first time the game is opened, it fades into the TUTORIAL instead (EXIT skips it, to the main menu). A refresh puts you back where you were: on the start screen until START is pressed, then on the main menu or in the game, with whatever was open still open (the MENU on its tab and sub-tab, scrolled where it was; SETTINGS; the MUSIC PLAYER) or the TUTORIAL at the step it was on, BACK still working (). Coming back to the app or tab carries on where you were.

MAIN MENU (#home, script.js's showHome): between the start screen and a game. The title and level bar, the six modes in a 3x2 grid (DAILY, CLASSIC, PUZZLE over BLITZ, VS, ZEN: CLASSIC top center), and the picked mode's panel: its name, what it is, its options (CLASSIC's difficulty, DAILY's game, PUZZLE's puzzle), your best (DAILY: today's official score once played) and PLAY. With a game of that mode under way (a drop made; paused) PLAY reads RESUME and carries on; picking another mode then asks first (CONFIRM?), as a restart does, and resets without the melt (the board is hidden). Under the panel, RULES & RECORDS and SETTINGS, then EXPLOITS and STORE buttons open those panels, and TUTORIAL under them (a game under way asks first; on the Google Play release a newer version adds UPDATE on a row of its own under it), each panel a card of its own covering the game card: ← BACK (or Esc) closes it, a tap beside it doesn't, and the corner icons hide while one is open. In a game (not the tutorial) the game screen is the title, the mode's name under it (// CLASSIC // NORMAL, // BLITZ, // PUZZLE 3, // DAILY DECRYPT // PRACTICE), the HUD and the board: the top-right icon is PAUSE (← BACK, top left, to the menu, when there's nothing to pause: VS's setup screen), and SETTINGS waits on the pause screen.

PAUSE (every mode but the tutorial; the top-right icon, or Esc / P): the board is covered as on VS's setup screen and the clocks stop (BLITZ's, the CPU's): RESUME, RESTART (VS: a new match with the same options) and, in VS, EXIT (back to its setup screen), the last two taking a second tap; RULES & RECORDS, SETTINGS and EXPLOITS open over it (every button under RESUME one size, two to a row, as on the main menu; no STORE in a game, it's on the main menu); QUIT (a second tap to confirm, CONFIRM?) ends the game, nothing kept, as RESTART, and goes to the main menu (a PUZZLE: to the PUZZLES list). A pause pressed mid-drop opens once the drop finishes. The game over box has MAIN MENU under NEW SESSION.

BACK (the phone's back button, or the browser's): a small card open over everything (an [i], the PATCHES or EXPLOITS card, GAME SETTINGS) closes first, leaving what's under it (the card's own ← BACK does the same: closeOverCard); then an open panel (MENU, SETTINGS, the MUSIC PLAYER) closes; in a game it goes to the main menu (a game under way pauses, for RESUME); on the main menu it goes back to the start screen (through black, as it went in); from the start screen it leaves as usual. The tutorial stays put (it has its own EXIT) (js/start.js).

SCREEN SAVER (js/saver.js; SETTINGS → SCREEN SAVER, on by default): after 90 seconds without a touch or a key (never while a timed game runs: a BLITZ clock or a VS match), a quick pixelated fade (black blocks filling in, in a random order) to a black screen with the wanderers doing their thing, visitors, seasons and all, at a height that moves every minute (no burn-in). To save battery everything behind it rests: the background animations stop, the card's wanderers go, the menus and the player close; the music plays on. A bot can be poked as ever; a tap anywhere else, or a key, wakes it (the blocks breaking up, quicker), and that tap goes no further. On the start screen one to four of the CPUs (BOT, GRIFTER, BUNKER, GLITCH; never two of the same; each arriving with a face, mostly EASY (35%) and NORMAL (45%), the angry HARD (14%) and red-eyed INSANE (6%) now and then) wander along the bottom of the card. They have MINDS (js/wanderers.js): each a personality (BOT curious and cheery, GRIFTER social and greedy, BUNKER lazy and cautious, GLITCH impulsive and mischievous) and needs that drift (ENERGY, spent walking; SOCIAL, wanting company; FUN; and TEMPER). Its TEMPER is its face, the difficulty faces as moods: calm EASY, even NORMAL, cross HARD, fuming INSANE. Poked, scared or robbed of a fish it gets crosser (a "grr" as it turns HARD), and a HARD or INSANE one snaps when poked, so poke a calm one a few times and watch it climb, then snap; good things (a snack, company, a catch) and time calm it back to its own calm. At each stop it does what it needs, weighed by who it is: rests when tired (BUNKER most), hops, snacks (GRIFTER most), puts on headphones (GLITCH most), goes over to another when lonely, fidgets when bored. It notices things: it wanders over to watch a bot fishing, joins a headbanging bot (with headphones), turns to look at a visitor going by. A tired one walks slower, and BUNKER or a tired bot headbangs where the others windmill. Meetings come as often as they want company, and a cross one is annoyed in them. The BOT SANDBOX's MINDS panel shows each one's face and needs, live. They keep their minds between visits (one of each bot: the same one comes back), as they left, eased by the time away: rested, its temper cooled toward its own calm, so a bot you made cross comes back still a little cross a while (kept in this browser). Looking the way they walk (eyes and mouth a pixel that way): in from either side, idling (now and then bored or tapping a foot), finding a free spot and heading back out. Two that meet may stop no closer than an arm's overlap, face each other and pull faces (a mood each and a little emote); a stop can bring a hop or two. Arrivals: 10% pop into view pixelated, 15% come in at a run and stop, tired, to catch their breath, the rest walk in. Departures: 5% decrypt away in a burst of pixels, 15% get spooked (scared, "!") and bolt, the rest walk off. A pop, a decrypt or a bolt startles every bot within 110px (surprised, facing it), cutting short any meeting there; a partner out of range is left -- (only bots on the card react: one still walking in keeps coming). Each picks a spot clear of the others standing or already headed somewhere, so even four at once on a narrow card stand apart; too many on the card leave one at a time. The game card's wanderers wait while the start screen covers it. Each bot keeps to its character: GLITCH is never happy, heart-eyed or laughing (nor shows EASY's smiling rest face); emotes fit the face (no <3 on a --), and the mad ones (HARD's angry and INSANE's red-eyed rest faces) and GLITCH never show the cheery ones (<3, ^^, haha); love comes only from the EASY and NORMAL faces, and never toward a worried, scared or put-out partner. Tap a wanderer and it reacts: 40% of the time it's startled and bolts; otherwise it's put out (-_-, "hey!"), shakes itself off in a puff of dust as if the touch left it dirty, then turns to you with a raised eyebrow (the SKEPTIC face) before wandering on. The mad ones (HARD's angry and INSANE's red-eyed faces) never bolt: they shake their head in whole pixels, no tilt ("grr"), bare their teeth (SNARL) and snap at you like a rabid dog, three lunges with the jaw chomping ("SNAP!" / "CHOMP!"), then 35% of the time stomp off at a run, still angry, or glare a moment and wander on. One poked while half on the card reacts right there, peeking in.

Seasons (js/seasons.js, by the player's own date; the dev page's SEASON switch, or ?season=halloween, forces one or turns them OFF). They STACK: when several are on at once (Hanukkah during winter, Christmas and Kwanzaa overlapping), each adds its touches, a bot picks its costume from any of them and the visitors and scenery come from all of them. The windows: HALLOWEEN Oct 1 to 31, NOVEMBER the month, WINTER Dec 1 to Jan 6 (the base under the December holidays), HANUKKAH its eight nights (a table of first nights, 2025 to 2035), CHRISTMAS Dec 18 to 26, KWANZAA Dec 26 to Jan 1, NEW YEAR'S EVE Dec 31 and NEW YEAR Jan 1 and 2. Forcing a holiday brings WINTER along with it. HALLOWEEN (October 1 to 31): most wanderers (80%) arrive in costume, drawn in their own pixel grid over the body and under the face, so every face, hop and snap still shows: BUNKER is a pumpkin (its face the carved one), BOT a see-through bedsheet ghost (80% opaque; it still walks, its legs showing under the hem), GRIFTER wears a witch's hat and GLITCH devil horns and a tail. All four dressed up on screen at once earns the hidden COSTUME PARTY. A wanderer that stops sometimes has a snack (30%): one to three gummy drops (2x2 pixels, a random bright color), each pulled from its side and tossed in an arc over its head into its mouth (hopping pixel to pixel), a munch and a chew; SWEET TOOTH (hidden) for 100 of them.

Winter and the holidays (costumes for any bot, mixed across the seasons on; a hat hides the antennas and ear tips under it). WINTER: a striped knit BEANIE with a pompom, EARMUFFS, a SCARF (blue or green); cookie bites as the snack. HANUKKAH: a blue-and-white beanie or scarf; gelt (gold) as the snack. CHRISTMAS: a SANTA HAT, an ELF HAT with a bell, or ANTLERS and a red nose; candy-cane bits as the snack. KWANZAA: a red-and-green scarf. NEW YEAR'S EVE and NEW YEAR: striped PARTY HATS. Snow falls all winter: pixel flakes drifting down the lane to the floor, a moment there and gone. At the new year, FIREWORKS go up now and then (a rocket, then a burst of pixel sparks that fall away). At the player's own midnight on New Year's Eve, every bot on the card counts down from ten, one says HAPPY NEW YEAR (the rest WOOO!, YAY! or the year) and the sky fills with fireworks (MIDNIGHT, hidden).

Visitors (js/visitors.js) pass through the same lane, one visit at a time every 20 to 45 seconds, in from either side. HALLOWEEN: FRANKENSTEIN'S MONSTER (lumbering, arm out), a MUMMY (shambling, a loose bandage swinging), the CREATURE from the black lagoon (waddling, dripping water), NOSFERATU (gliding), a see-through GHOST (floating), a flock of BATS (flapping across), a CROW or two (hopping in, pecking, then flying off, wings open and flapping) and a SPIDER (down on its silk thread somewhere along the card, a dangle, back up). NOVEMBER (the whole month; nothing holiday-specific): a TURKEY struts in, pecks a while and struts on (and the crows), and MIGRATING BIRDS fly over: geese in a V (honking now and then), ducks in a line, a loose flock of songbirds (robins, bluebirds, goldfinches or cardinals) or swallows swooping fast. About a third of the time one drops out, lands, pecks about and calls (HONK! QUACK! TWEET! CHIRP!) to the nearest bot, which reacts, then flies off after the others; poked, the whole flock bolts up and away. Any time of year, with music playing, a bot may walk in wearing HEADPHONES (1 in 10) or stop and put a pair on (15% of its stops): then it vibes, eyes closed (♪). Standing, it moves to the drums: a nodder (6 in 10) nods on the kicks, at most every half beat, and a tapper taps its foot on the hi-hats, at most every eighth (the music engine logs each drum hit as it schedules it, kicks, hats and snares, and the bots move as each is heard); with nothing to follow (a breakdown) they keep time anyway, a nod each bar, a tap each beat. Walking, its steps fall two to a beat (kept in sync as the tempo moves). CORE DUMP (track 09) tells its feel, and to it the headphone bots go metal, in poses drawn as pixel sprites: they grow long hair, and in the gallop they HEADBANG, four frames a beat (up, tilting forward with the hair falling over the brow, bent face-down on the beat with the top of the head to you, the headphones' band across it, the eyes and mouth just peeking at its lower edge and a few strands hanging off the face, tilting back), a fist raised beside the head with the metal horns up; the half-time breakdown's bang holds face-down longer, on 1 and 3. In the blast beats they WINDMILL (drawn in the dev page's FRAME EDITOR, js/data/bot-anims.js): eight frames over two beats, starting on the even beats, the hair flung straight up, swept over to the right as the head pitches down, covering it at the bottom of the swing, round the left and flung up again as the head comes back up; in each bot's own colors, mirrored when it faces left. The hair is near-black with a cool sheen. The hair goes when the track does. It keeps them on until it leaves; if the music's switched off, it goes -_- and puts them away. Besides the scary tree, a bot may push in a JACK O' LANTERN: a carved grin lit from inside, its candle flickering; poked, it flares up and cackles (HAHAHA!), the bots near it jumping. HALLOWEEN also sends the GREMLIN: a little green creature with big ears, red eyes and a toothy grin that scurries up to one bot after another to prank it (hehehe; the bot jumps), then runs off; poked, it screeches (SKREE!) and bolts. Now and then (15% of NOVEMBER's visits, and HALLOWEEN's) a FOG rolls in instead (on HALLOWEEN, scarier: it becomes the HAUNTED FOREST, below, and out of the fog comes either the wanderer, its eyes glowing red as it moans ooOOoo, or (60%) one of the monsters, Frankenstein, the mummy, the creature, Nosferatu or the ghost, fading in by a tree near one side, crossing, and fading back into the mist before the other; most bots it nears bolt): a heavy bank of coarse-pixel mist drifts in from one side and fills the lane (rising a little above it and thinning out; on the start screen only its lower part, clear of the title; the twinkling background behind it fading to black as it thickens). The fog is fog alone; THE WOODS are a backdrop that comes with it only late in the year (October's HAUNTED FOREST, November, the winter): pines and bare trees fading in through it one by one as the bank reaches each, dark against the mist, the far ones fainter. The spring and summer mornings' mists (WEATHER) come without them. It comes to the screen saver too (its lane 90px tall for it, the mist fading out at its ends). Once it's built, the FOG WANDERER (a pale hooded figure with glowing eyes and a trailing hem) may come: every October fog has it (or a monster), November's half the time, the winter's now and then, the rest of the year's never (a quiet mist that hangs heavy a while, then thins). It fades out of the mist, drifts from spot to spot (a bot it nears jumps, or bolts) and fades back into the mist (poked, it's gone at once). The fog then thins to a light mist (the trees, if any, standing in it) for two minutes, and lifts. While it's heavy nothing else comes by and the bots keep to themselves, walking slower (no meetings, snacks, hops or pushed scenery; now and then a worried ? or ...); two that walk into each other jump apart (!?), and now and then one bolts. The dev page's FOG: OFTEN brings it at the next visit, in any season, its light mist lifting after 20 seconds (or ?fog=1).

OCTOBER's scares. On HALLOWEEN (the whole of October) the fog is the HAUNTED FOREST, and once it's come it STAYS, on every card (the start screen, the game card, the screen saver) for the rest of the month while the game's open (not kept once it's closed); till it's come, a visit that comes due in October is the forest's fog 45% of the time (15% in November): pines and bare, twisted trees, bigger than November's and a shade lighter so they show against the dark, and two big gnarled trees in front of everything at either edge, the path the bots walk between them. The mist never lifts; it breathes, thinning and thickening a little, and now and then swells heavy again for its wanderer (or a monster) to come out of. In the forest: GLOWING EYES blink between the trees (yellow, red or green, a pair or three, edging after the bots; poked, they shut); and rarely the BLOOD FOG: the mist thickens and turns from white to red as a blood moon rises behind the trees, and the red-eyed wanderer comes out of it after a bot, which runs for it; then the red drains away and the moon sinks. Anywhere in October: the WEREWOLF (the old movie kind, a man gone to fur: pointed ears, yellow eyes, fangs, his work shirt and trousers, clawed hands; night falls on the card and a pale full moon rises; he walks in, stops and howls AWOOOOOO (eyes shut, mouth wide), the bots near him bolting and the rest jumping, then runs off; poked, a growl and off), LIGHTS OUT (the card goes dark, flickering, nothing but the bots' eyes blinking in it; when the lights come back on one of the bots has moved, or a monster stands among them, red eyes showing in the dark first), the HAND (the floor rumbles under a bot and a hand comes up and grabs it; it struggles, breaks free and runs; poked, the hand lets go) and the POSSESSED bot (red, glowing eyes and a stiff, slow walk; the others it meets are scared of it; poked, it shakes, a little ghost shakes out of it and floats away, ooOOoo, and it comes to, dizzy). The bot sandbox has each on a button (OCTOBER SCARES).

Any time of year, rarely (6% of the times a visit comes due, about one every ten minutes): a VIRUS, one of three. The PHAGE, a bacteriophage taller than the bots (a hexagonal blue head with its pink DNA coiled inside, a striped tail, and four kinked tail fibers it walks on, stepping in turn); the BUG, a spiky little red one that scuttles fast; and the TROJAN, which walks about as one of the bots (any of them) and scares no one, until it's poked: the disguise pixelates off, a wooden horse on wheels with a red eye pixelates in, laughs (HEHE) and bolts, the bots near it jumping. Each walks in from a side or pixelates in right on the card, scuttles from spot to spot with the odd lurch and glitch (0xBAD, >:), hehe) and walks off; a bot it comes near jumps. Poked (a TROJAN: once it's unmasked), it's DELETED: it either bursts into its own pixels, each a fragment in its own color (as a bit bursts, finer), or deteriorates, its pixels dropping out in a random order, in steps, as the screen does going into the screen saver. The dev page's VIRUSES: OFTEN brings one every few seconds, the three in turn (or ?virus=1). They're pixel sprites in the bots' pixel size and sway and bob in whole pixels, on the same floor as the bots (their feet two pixels of the grid above the lane's edge); they walk behind the bots, bats and crows over them. A monster passing a bot may give it a fright. Poke one: the monster roars and stomps (bots near it jump), the mummy groans and slows, the creature splashes, Nosferatu hisses and turns into three bats, the ghost says BOO (every bot near it jumps) and fades away, the bats scatter, the crow caws and takes off, the spider scurries back up (bots near it jump) and the turkey gobbles and runs. MONSTER MASH (hidden): meet all eight Halloween visitors; GOBBLE GOBBLE (hidden): meet the turkey. WINTER: now and then (3 in 10) a bot skates in instead of walking: blades under its feet, leaning into long pushes and glides, kicking up a trail of powdered ice that melts away over a few seconds (a spray of it when it skids to a stop; fewer flecks on REDUCED EFFECTS). It skates around a bit and out like any other. A PENGUIN waddles by (poked: SQUAWK and a belly slide off; BELLY SLIDE, hidden). CHRISTMAS: a REINDEER trots past, now and then (25%) the one with the glowing red nose (RED NOSE, hidden); poked, it snorts and prances off. HANUKKAH: a DREIDEL spins in, wobbles to a stop and lands on a letter (NUN, GIMEL, HEY or SHIN; GIMEL, hidden, for seeing it land on GIMEL), then spins on its way; poked while it's down, it spins again to land on another.

Scenery. HALLOWEEN: now and then (15% of arrivals, one at a time) a wanderer comes in pushing a SCARY TREE (a dead, gnarled tree with black eyes and a frown) ahead of it, slowly and straining, sweating; it leaves it standing somewhere along the card, says "phew" and wanders on. The tree stays for the visit, behind every bot and visitor but in front of the start card's copyright line. Poked or startled mid-push, the pusher lets go (the tree stays where it stopped) and reacts as usual. Poke the tree: it creaks and a bat flies out. UPROOTED (hidden): see a tree pushed in. The other seasons push theirs in the same way: WINTER a SNOWMAN (poked: brrr! and a shiver; SNOW DAY, hidden) or the CHRISTMAS TREE, CHRISTMAS that decorated EVERGREEN with warm filament bulbs (warm white, amber and red) glowing and blinking in turn, a twinkling star and presents under it (poked: jingle!, its lights flash), HANUKKAH a MENORAH with that night's candles lit and the shamash (the flames flicker; EIGHT NIGHTS, hidden), KWANZAA a KINARA (three red, the black, three green) with that day's candles lit, the black first and then from the outside in (SEVEN CANDLES, hidden), and NEW YEAR'S EVE and NEW YEAR a SIGN with the new year on it (poked: HAPPY NEW YEAR! and a firework). Up to two pieces stand at once, one of each, each at a spot clear of the other (and of the path to it: nothing is pushed through anything). Menorah, kinara and sign are never mirrored.

The same wanderers stroll along the bottom of the game card too, between the corner buttons (walking out from behind them), with everything above: meetings, frights, pop-ins, decrypts and pokes. On the game card their lane reaches up to the bottom edge of the grid's card, and the whole game (the HUD, the grid's card, the drop buttons, the exploit button and its side slots, the message) stays on top of it: what flies there passes behind them, and LIGHTS OUT, the night and the fog fill the lane under them. SETTINGS → WANDERING BOTS turns them off (on by default). The engine is js/wanderers.js, shared by both cards. On the start card the lane is the whole card: the bots walk along its bottom, and what flies, falls or hangs uses all of it (bats anywhere up the card, the spider dropping from the top edge behind the title, crows climbing off across it, snow falling from the top, fireworks bursting high). In the game the lane is the card's full width along the bottom, with the heights as before. They pass under the drop buttons and the message line below the grid (bats, crows and the spider's thread included), and a poke leaves no tap box around them.

Bot achievements (RECORDS, the BOTS group): POKE, BOO! (poke one so hard it runs), THE EYEBROW (a raised eyebrow from all four bots), THIRD WHEEL (poke one mid-conversation), MATCHMAKER (two fall for each other), JUMP SCARE (a pop-in startles another), NOW YOU SEE ME (one decrypts away), FULL CREW (all four on screen at once), and hidden: PERSONAL SPACE (100 pokes), HR WANTS A WORD (200), RABID (get snapped at by a mad one) and DEVELOPER OPTIONS (tap the VS CPU seven times in a row: "YOU ARE 3 TAPS AWAY FROM BEING A DEVELOPER" ... "NO NEED. THERE IS NO DEV MODE HERE."). The faces include the CPU's moods plus SCARED, TIRED (panting), SURPRISED, LOVE (red heart eyes), DIZZY and LAUGH. The small faces come from js/minibot.js, a copy of the CPU's face for use anywhere.

Music player

Its top is a game's: ← BACK in the corner, BYTEFALL in the same place and size as everywhere else, and // MUSIC PLAYER under it as a game's mode line; the visualizer, the controls and the tracks scroll under that. (No scroll bars show anywhere in the game: menus, cards and lists still scroll by touch, wheel or keys.)

GENERATED (track 16, free all year, ahead of tracks 12-15; js/music/music-generated.js) writes itself. It's seeded: the SONG OF THE DAY is the date's, a new song each day that everyone hears the same; tapping track 16 while it plays switches to RANDOM (a new song each time it starts) and back. SHUFFLE plays the official tracks only. The play mode RADIO (after REPEAT, SEQUENCE and SHUFFLE) is mostly new RANDOM songs, with the SONG OF THE DAY and the unlocked tracks now and then (about 3 in 4 new songs), each played twice through; NEXT is its next pick. The seed picks a style from the season's: all year SYNTHWAVE, CHIPTUNE, DRUM & BASS, LO-FI, TECHNO and DREAMWAVE; Halloween HAUNTED WALTZ (3/4), MONSTER SURF, HORROR SYNTH, GRAVEYARD MARCH and MUSIC BOX (a warped 3/4 lullaby); November HARVEST JIG (6/8), CAMPFIRE, HOEDOWN and AUTUMN LO-FI; December SLEIGH RIDE, SNOW WALTZ (3/4), CAROL and COZY LO-FI; FROST (Jan 7 – Feb) AURORA, ICE CAVE, SNOW DAY and FIRESIDE LO-FI; VALENTINE'S (Feb 7 – 14) LOVE BALLAD, SLOW JAM, SWEETHEART WALTZ (3/4) and SYNTH CRUSH; SPRING (Mar – May) MEADOW FOLK, APRIL SHOWERS, GARDEN WALTZ (3/4) and BLOOM; SUMMER (Jun – Aug) BEACH SURF, ISLAND BREEZE, SUNSET HOUSE and ARCADE SUMMER; SEPTEMBER BACK TO SCHOOL, GOLDEN HOUR, EQUINOX LO-FI and PORCH SWING (the all-year styles come back with the SONG CODES' D). Then everything else: the key and mode, the tempo (in the style's range), the form (INTRO, A, B, a bridge with the beat dropped out or a breakdown, sometimes the last part a step up), the progressions (a hand-picked stock, only true major and minor chords in the mode; the V made major in the minor ones), the hook (a two-bar rhythm built a beat at a time, landing on the chord's notes on the beat and moving by step between, said, answered, said again and brought home), the bass line (root, octaves, walking, oom-pah, acid...), the arpeggio or strumming, the groove and its fills, the instruments (organ, choir, strings, Rhodes, music box, theremin, fiddle, flute, pulse waves, a reese bass...) and a title. The MUSIC PLAYER shows the song's title and style; SETTINGS, under the playlist, today's. Every song has a SONG CODE (H1-0KUP3YT: its season, H Halloween, N November, W winter, F frost, V Valentine's, S spring, U summer, A September, D the all-year styles; the generator's version; its seed). The MUSIC PLAYER shows the playing song's (tap it: copied), SHARE copies its name, style and code ("PUMPKIN LULLABY" (MUSIC BOX) on ByteFall // song code H1-0KUP3YT), and ENTER SONG CODE plays the song a code names on track 16 (any case, the dash optional), so a RANDOM song can be heard again or shared. A code from a newer ByteFall says to update. When a change to the generator would alter the songs already written, the old generator is frozen as its own file (how, at the top of music-generated.js) and loaded only when one of its codes is entered, so old codes keep playing their songs. Layered like the others, building with the stack.

The SEASONAL theme's audio: picking the SEASONAL theme puts on GENERATED and the season's sound effects (October: HAUNTED, also a SOUND EFFECTS choice of its own all year: creaks and knocks, a cold wind, a music box, glass chimes and a church bell, in A harmonic minor; FROST: ICICLE; VALENTINE'S: SWEETHEART; SPRING: BIRDSONG; SUMMER: ISLAND; SEPTEMBER: SCHOOLYARD), as a starting point: either can be changed after. Picking another theme puts back the track and sounds from before (if they're still the seasonal ones).

SETTINGS → GAME MUSIC: LAYERED (the default: the music builds with your stack, more layers coming in as the danger climbs) or FULL (every layer in the whole game long, as in the music player; STACK OVERFLOW then runs at its top speed). SETTINGS → PLAYLIST → OPEN MUSIC PLAYER opens the soundtrack on its own, over the whole page (its ×, Esc or the phone's back return to SETTINGS): every track plays as its full mix (all layers in, whatever the game was doing), with a big visualizer: tap it to cycle SPECTRUM (LED bars), WAVE, OSCILLOSCOPE (a few cycles held still on a rising zero crossing, over a graticule), RADIAL (spectrum bars around a ring that swells with the bass), PARTICLES (a liquid blob morphing with the spectrum, shedding particles as it gets louder) and VECTORSCOPE (left against right turned 45°, with a phase-correlation meter; every track is in stereo; a mono sound shows as a vertical line at +1), STEREO FIELD (the vectorscope with the side given its own scale, so the quieter stereo parts fill the width and the cloud leans to whichever side plays; the meter still reads the real stereo), LISSAJOUS (left across, right up, each at its own scale; a mono sound is a diagonal), its name shown top left. The visualizers follow the theme (its bit and accent colors; a cycling rainbow in SPECTRUM). Also: SPECTROGRAM (the spectrum as a heat-map scrolling left), LEVEL METERS (L / R LED ladders with peak holds), MATRIX RAIN (0s and 1s falling, each column a band), BIT GRID (an 8x8 board, HARD's, stacking bits per band, a full column flashing), SYNTHWAVE GRID (a sun on the horizon, and one wireframe landscape rolling toward you: flat down the middle like a road, rising at the sides into jagged spikes that travel with the grid, tallest at the lower outer edges and fading out toward the vanishing point; the music lifts them, the bass nearest the road and the treble at the edges), PLASMA (a color field warped by the bass), TUNNEL (rings rushing toward you on the beat) and ORB (a sphere of particles in the middle turning slowly clockwise on its tilted axis, each patch of it swelling out and glowing with its own part of the spectrum: the bass around its foot, the treble at its crown; in the theme's colors), OCEAN TOPO (the same traveling sea drawn as a map's contour lines over hills of its own, fixed on the sea so the rings flow by as it travels and turns, the music raising them; a ring for each height: as the sea rises its higher rings appear, as it falls they shrink away; the highest in the accent), OCEAN DEPTHS (the same traveling sea as its points alone, each with a thin line hanging straight down from it into the depths, fading to black the deeper it goes; the points on OCEAN HEX's honeycomb, which leaves the fewest open lanes between them), OCEAN GRID, OCEAN MESH and OCEAN HEX (a sea of particles out to the horizon and past every edge, each joined to its neighbors by a thin line, a square grid, a triangle mesh or, in OCEAN HEX, a honeycomb, fading with the distance; traveling over it in a slowly wandering direction, the view slowly turning about as it goes (now one way, now the other; mostly looking where it's going), and endless: its swell is one big square tile mirrored on all four sides; the music swims in it as soft round swells under the surface, each one band of the spectrum (the bass broad, the treble small), drifting and wandering about the sea, coming up ahead and fading as they pass, easing off right in front of the view), TOPOGRAPHY (contour lines over hills the music raises, one per band, drifting; the highest rings in the accent) STAR FIELD (flying through a galaxy as a galaxy map does: star systems all around in open space, near ones bigger and brighter, far ones fading into the dark, the view sailing on through them on a slowly wandering course, turning and rising and dipping, a little faster with the music; each star listens to a narrow band of its own picked at random anywhere from 20Hz to 20kHz (evenly by pitch, so lows, mids and highs alike; a sixth of an octave to most of one wide) and swells and brightens as its band rises above what it's been doing lately (its own floor and peak, so the stars move each their own way), at its own pace, some quick to flare, some slow to rise and settle, and twinkles at its own rate; in the SPECTRUM theme each is colored by its pitch; a few are of the accent's color, and the big ones glow) and PARTICLE CLOUD (a swarm loose in open, endless 3D space, the view following it as it drifts and circling it slowly like the ORB turns, the far particles fading into the dark; with no music a murmuration, a few flocks following wandering leaders, wheeling, merging and splitting; the music stirs it: the bass puffs the flocks outward (they gather back), each particle's own band kicks it about, louder is faster, the loudest glow in the accent). Under the visualizer hang two tabs: STYLES (lower left) pulls out a drawer over the controls with every style by name, in groups (CLASSIC: SPECTRUM, WAVE, OSCILLOSCOPE, SPECTROGRAM, LEVEL METERS; STEREO: the VECTORSCOPE, STEREO FIELD, LISSAJOUS; SHAPES: RADIAL, PARTICLES, ORB, PLASMA, TUNNEL; RETRO: MATRIX RAIN, BIT GRID, SYNTHWAVE GRID; OCEANS: GRID, MESH, HEX, DEPTHS, TOPO; LAND & SPACE: TOPOGRAPHY, PARTICLE CLOUD, STAR FIELD; a tap on the visualizer cycles them in this order too; a tap on a name goes straight to it; a tap elsewhere puts it away); under the styles, the style showing's own SETTINGS, saved per style, in real units where there are any: SPECTRUM bars, peak fall (heights/s), treble lift; WAVE height, line and glow (px); OSCILLOSCOPE time shown (ms), height, line; SPECTROGRAM bands and scroll (px/s); LEVEL METERS range and peak fall (dB, dB/s); RADIAL spokes, ring size, spin (RPM); PARTICLES amount, blob size, trail; the VECTORSCOPE three dots (px), zoom, trail; MATRIX RAIN character size (px), speed, trail; BIT GRID board size and drop (boards/s); SYNTHWAVE GRID speed, peak height, the sun on or off; PLASMA speed and pixel size; TUNNEL sides, speed, sway; ORB particles, spin (RPM), size; the oceans' DENSITY (how many points are in view at once, on screen out to where they fade away, the same on any screen, with the count drawn just now beside it; defaults GRID 1,250, MESH 740, HEX 520, DEPTHS 1,100, at most 3,000 for DEPTHS), speed and turning (°/s at most), DEPTHS' line depth, OCEAN TOPO's contours; TOPOGRAPHY contours and drift; PARTICLE CLOUD particles, flocks, spin; STAR FIELD stars, speed (light years/s), turning, star size (a trail is a half-life in ms: how long a mark takes to fade to half); DEFAULT puts this style's back, ALL DEFAULTS every style's, and FULL SCREEN (lower right) puts the visualizer edge to edge (the browser's full screen too, and the screen kept awake; it turns with the phone, landscape or portrait, even with the phone's rotation locked in the app): a tap on the outer quarter at either side switches styles (left the one before, right the next) and a tap anywhere between plays or pauses the music (a sign flashing in the middle), the name and the way out fade after a few seconds untouched, and the corner button, Esc or back come out. Between the tabs, SOURCE picks what the visualizer shows: BYTEFALL (its own music) or, in the Android app, OTHER APPS (whatever the phone is playing, Pandora, Spotify and all: from Android 10 on by audio playback capture, the way a screen recorder hears it, the sound itself in stereo, analyzed as the game's own music is; Android asks once for the audio permission, called record audio, then each time OTHER APPS starts it asks to start recording or casting (the whole screen), though nothing is recorded or kept; a notification shows while it listens, with STOP (the corner then says STOPPED: TAP SOURCE, and a tap listens again); it listens on with the player shut, so Android needn't ask again, until another source or the app closes; apps can refuse to be heard, and a few do; before Android 10, through Android's Visualizer on the output mix; , , ), and MICROPHONE (whatever plays out loud), or on the web MICROPHONE only (a page can't hear other apps); a tap moves on to the next, and while one listens the corner shows what's coming in (IN: LEVEL n, or by capture its loudest in DB (0 the loudest a sound can be, -20 loud, -60 faint), SILENT (nothing but silence coming over: the app playing won't be heard) or NO DATA). Switching to it pauses ByteFall's music; in FULL SCREEN the middle tap does nothing then (the other app plays and pauses its own music). The SCREEN SAVER never comes on over the MUSIC PLAYER. With nothing playing, every style keeps moving gently: the ones that would sit empty (SPECTRUM, OSCILLOSCOPE, SPECTROGRAM, LEVEL METERS, RADIAL, the VECTORSCOPE three, BIT GRID, TOPOGRAPHY) show a calm made-up signal, as WAVE always has. The small one in SETTINGS has the ones that read at its height: SPECTRUM, WAVE, OSCILLOSCOPE, SPECTROGRAM, LEVEL METERS and PLASMA; PREVIOUS / PLAY-PAUSE / NEXT, REPEAT / SEQUENCE / SHUFFLE, the 16-slot track list (locked tracks show the level they open at; tapping the track playing switches STACK OVERFLOW to STACK OVERFLOW - FULL SPEED, held at its top tempo, and GENERATED to RANDOM, and back) and BACKGROUND PLAY, so it can run on a phone with the screen off. Keys: Space plays / pauses, ← / → skip, Esc closes. Where the browser offers them, the lock screen's media controls work too. The game waits underneath (a VS match pauses). Code: .

Sound effects themes

SETTINGS → SOUND EFFECTS picks the game's whole set of sound effects, each in the style of one of the tracks (js/sfx.js). TERMINAL, the first and free: the keyboard's clicks and keys, line static and an 8-bit crunch. HANDSHAKE, opening with the HANDSHAKE track (TRACK 10, Lv 29): a handheld console's, as in that Game Boy battle theme, tuned to its C minor: pulse-wave blips for the cursor and buttons, a wave-channel thud as a bit lands, the noise channel's metallic crunch as one decrypts (with a note of the scale each time, so a chain plays a little tune), an item-get arpeggio for a chain or a reward, the battle's low-HP alarm for a warning and a low buzz for no. The dial-up and the narrator's voice are the same in every theme. The seasons' (the SEASONAL theme puts each on in its time, and each is a choice of its own all year): HAUNTED (October), ICICLE (January and February: glass pings, ice cracking, a cold wind and bells, in D lydian), SWEETHEART (Valentine's: a harp, a heartbeat and a kiss, in F major), BIRDSONG (spring: birds, raindrops, a woodblock and a marimba, in G major), ISLAND (summer: a steel pan, a shaker, bongos and the waves, in C major) and SCHOOLYARD (September: pencil taps, a xylophone, chalk, lockers and the school bell, in A major). The dev page's ONE-SHOT EFFECTS plays every theme's take. In every theme, a bit falling through the grid (or settling after a clear) ticks a row at a time, each tick a little higher or lower than the last, wandering as the tutorial BOT's voice does.

Effects

SETTINGS → EFFECTS: FULL / REDUCED, for slower phones: REDUCED holds the twinkling grid backgrounds still (the board's, the HUD boxes', the start card's), drops the glows (text and box shadows, repainted with every change) and bursts bits into fewer, bigger pieces.

Sound output and instrument channels

SETTINGS → SOUND OUTPUT (js/music/output.js) picks what the music and sound effects pass through last: HEADPHONES (the mix as written: headphones, earbuds and good speakers), SPEAKERS (laptop and tablet speakers: the deep bass played as harmonics, the level evened out, about 3 dB louder above 250Hz) or PHONE (a phone's own speaker: the lows it can't play cut and put back as harmonics it can, folded to mono, 1–4kHz lifted, the hiss softened, about 7 dB louder above 250Hz). A page can't tell whether earbuds are in, so phones start on PHONE and everything else on HEADPHONES; the note under the button says to pick HEADPHONES with earbuds.

Every track routes each instrument through its own channel (kick, snare, hats, bass, lead, pads, echo returns...; echo and reverb sends follow their instrument), which change nothing at their default level: the split was checked by rendering each track's whole loop before and after with the same random seed and comparing sample by sample (NIGHT DRIVE with its ping-pong feedback off: with it on, even the original renders a little differently from run to run). The originals are kept in js/music/archive/. Mix tables in js/music/mixes.js (from the dev mixer's EXPORT) set each channel's level per track and output, at the four stack heights the game settles on, eased between as the intensity moves.

To-do

• CORE DUMP (track 09): its trial layers still wait for picks.
• Sound effect themes: more in the style of the tracks (TERMINAL and HANDSHAKE so far: SETTINGS → SOUND EFFECTS).
• Future games (separate from ByteFall): BYTERRIUM, a Tamagotchi-style spin-off for the CPU bots (its first piece is live: Byterrium), a Jumanji / Zathura-style board game of events the players survive together, and three Halo game types to rebuild in Halo Infinite (AVALANCHE, WARTHOG ARENA, PAC-MAN ARENA FIESTA). See TODO.md.

Seasonal stuff (ideas, by the player's own date)

Done: HALLOWEEN (costumes, candy snacks, nine visitors with the gremlin, the scary tree and the jack o' lantern, the HAUNTED FOREST and October's scares), NOVEMBER (the turkey, the crows, migrating birds), and the stacked December and new year seasons: WINTER, HANUKKAH, CHRISTMAS, KWANZAA, NEW YEAR'S EVE and NEW YEAR. Each new season plugs into the same pieces: a date window in js/seasons.js, costumes (wanderers.js), visitors and scenery (visitors.js), a snack, a step on the dev page's SEASON switch, and a hidden achievement or two.

• NEW YEAR, more: noisemakers ("toot!") and confetti.
• KWANZAA, more: a visitor or a harvest snack (fruit), if wanted.
• LUNAR NEW YEAR (a week from its date, which moves each year: a small table of dates): a dragon dance crossing the card (a long, segmented dragon), red lanterns pushed in as scenery, strings of firecrackers popping, red envelopes as the snack, and the year's zodiac animal as a visitor.
• WINTER, more: hot cocoa as a snack (a mug, steam), a snowball tossed between two bots, a sleigh crossing the start card's sky.
• SPRING (Mar 20 to Apr 30): a RABBIT hopping through, butterflies fluttering across (like the bats), flower pots pushed in, spring showers (a rain shower and a bot with an umbrella), chicks peeping after a hen.
• SUMMER (Jun 21 to Aug 31): sunglasses and sun hats, ice cream as the snack (it drips), a beach ball bouncing across, a crab scuttling sideways, fireflies in the evening (the player's local time).
• AUTUMN / HARVEST (Sep 22 to Oct 14): a SCARECROW as scenery (it stands on its post, so pushed in like the tree; the crows land on it and fly off when a bot comes by), falling leaves drifting down, pumpkins and hay bales.
• Small days (the game already has achievements for some): FRIDAY THE 13TH (a black cat crossing the card), PI DAY (the bots share a pie), the game's birthday (party hats), leap day.
• HALLOWEEN, more: a second costume per bot (skeleton, vampire cape, mummy wraps, a black cat), more candy kinds (lollipops, wrapped candies).