How to play
You're in a car driving from München to Berlin. Cars pull up next to you, and each one carries a German license plate like M·UM 517.
- Make a word from the plate's letters (3 letters or more). Use every letter for a jackpot.
- Numbers are letters in disguise:
0=O, 1=I, 3=E, 4=A, 5=S, 7=T, 8=B
- Answer in under 5 seconds for double points.
- Every word fills up your tank. Every car that gets away drains it. Run dry and the trip is over.
Words count in English, German, or both (you pick).
Game modes
| Mode | Players | How it works |
|---|
| Solo Cruise | 1 | Ride with Lukas (driving) and Mia (back seat). Beat your best score. |
| Convoy | 2 to 4 | Everyone in one car on their own phone. One shared tank and score. |
| Rally | 2 to 16 | Up to 4 team cars race to Berlin. First car there wins. 1v1, 2v2, 3v3, 4v4. |
Every trip is Quick (about 3 min) or Normal (about 7 min).
Pick your window seat
Each seat gives you a different view and different plates:
| Seat | What you see |
|---|
| Shotgun | Windshield. Cars in front of you. |
| Left window | The fast lane. Cars overtaking you. |
| Right window | Trucks and slow cars you pass. |
| Rear window | Tailgaters behind you. |
Boosts and pranks ⚡
Spend your points with the round Boost button:
| Boost | Cost | Per trip | What it does |
|---|
| 🛢️ Oil slick | 800 | 3× | The leading rival spins out. Their letters lock for 4 seconds. (Rally) |
| 🌫️ Fog bomb | 600 | 3× | The leading rival's letters go blurry for 7 seconds. (Rally) |
| 🚀 Turbo | 700 | 2× | Your car goes 60% faster for 10 seconds. |
| ⛽ Refuel | 500 | 3× | +40 fuel. |
| 🛡️ Shield | 400 | 3× | Blocks the next prank aimed at you. (Rally) |
Limits are per car, shared by everyone in it. Each car waits 25 seconds between boosts, and a car that just got pranked is safe for 20 seconds.
Everyone sees a big banner saying who did what: "DISHA OILED TEAM BLAU".
Watch out for gold plates. They're worth triple points.
Controls
| Action | Phone | Keyboard |
|---|
| Add a letter | Tap a tile | Type the letter |
| Remove a letter | Tap it in your word | Backspace |
| Submit | Submit | Enter |
| Shuffle tiles | Shuffle | 1 |
| Boosts | ⚡ Boost | 2 to 6 |
| Honk | Honk | Space |
| Hint (−50% points) | Hint | |
| Borrow a letter (−30%) | Wild | |
| Pause | ⏸ | Esc |
Install it like an app
- iPhone (Safari): Share → Add to Home Screen
- Android (Chrome): ⋮ menu → Install app
Run your own copy
Everything here is free: GitHub, Vercel (hosting) and Supabase (the live connection between phones).
1. Supabase
- Create a project at supabase.com (region Frankfurt is good for Europe).
- Open SQL Editor → New query, paste the contents of
supabase-setup.sql and click Run.
- Under Project Settings → API Keys, copy the Project URL and the publishable key (the "anon" key also works).
2. Add the keys
Paste both into config.js:
window.AA_CONFIG = {
supabaseUrl: "https://xxxx.supabase.co",
supabaseAnonKey: "sb_publishable_xxxx"
};
Is this safe in a public repo? Yes. The publishable key is made to be public. Every player's browser receives it anyway. Never put the secret or service_role key here.
3. Deploy on Vercel
- Import this repo at vercel.com → Add New → Project.
- Framework preset: Other. Leave everything else as it is. Click Deploy.
4. Check it
https://your-link.vercel.app/api/keepalive shows "ok":true- Vercel → Settings → Cron Jobs lists
/api/keepalive (runs daily)
- Open the game on two devices → Road Trip: the lobby says Online
Without keys, Road Trip runs in test mode: only tabs in the same browser can join. Handy for trying it out.
Try it on your computer
python3 -m http.server 8000
Then open http://localhost:8000 in two tabs.
What's in the repo
index.html The page
game.js Game, 2D road renderer, multiplayer
words.js English + German word lists (~50,000 words)
config.js Supabase URL + publishable key
api/keepalive.js Daily ping so the free Supabase project never pauses
.github/workflows/ Backup ping every 2 days from GitHub
vercel.json Runs the keep-alive once a day
supabase-setup.sql Creates the tiny keep-alive table
manifest.webmanifest Makes it installable as an app
sw.js Minimal service worker (needed for install)
icons/ App icons, favicon, logo, link-preview image
docs/ README screenshots
_head.html, build.py Source of index.html (edit _head.html, then run python3 build.py)
How it works
- No framework, no build step. Plain HTML, CSS and JavaScript. The road, cars, weather and window views are drawn live on a canvas.
- Multiplayer uses Supabase Realtime broadcast. There's no game database. The person who creates the trip runs the scoreboard, and if they drop out, the next player takes over.
- Words come from frequency lists, so plates use real, common words. Every plate is built so it has at least one good answer.
Free tier limits
- Supabase free: about 200 people online at once and 2 million live messages a month. A 6-minute trip with 4 players uses roughly 3,000.
- Vercel Hobby: free for personal, non-commercial projects.
- Supabase pauses free projects after 7 days without use. Three things stop that: a daily Vercel cron (
/api/keepalive), a GitHub Action every 2 days (.github/workflows/keepalive.yml), and every online game. Each one calls ping(), which writes a timestamp to the database.
Troubleshooting
| Problem | Fix |
|---|
| Lobby says Test mode | The keys in config.js are empty or didn't save. |
| Lobby says Connection problem | Supabase → Realtime → Settings → allow public channels. |
/api/keepalive shows an error | The SQL step didn't run, or the key in config.js has a typo. |
| Old app icon on your phone | Delete the home-screen icon and add it again. |
License
MIT. Use it, change it, share it. Just keep the copyright line.
