Amhiti Adventures

A vibe coded game for Mudita, Dayananda Sagar College of Engineering — built for Amhiti 5.0, the annual mega donation drive.

"A helping hand for a hopeful heart."

The UI takes its palette straight off the Amhiti 5.0 poster: the deep teal it is printed on (#154854), the mint crumpled paper the artwork sits on (#b0d7d3), black ink, and the warm orange and yellow of the donated books spilling out of the box. The city keeps its golden hour — warm low sun against cool teal glass is the poster's own pairing.

A browser arcade-driving game. A Mudita tempo leaves the DSCE gate loaded with donation crates and has to reach the orphanage on the far side of the city in under 40 seconds, with the load still in one piece.

It runs at golden hour: the sun sits low and orange on the horizon, the sky above it goes violet, and the city has its lights on. The key light is warm and the sky bounce is cold, which is the whole reason an evening reads as an evening instead of a beige noon — and it means the long shadows rake straight down the streets you are driving.

No build step, no bundler, no binary assets — every texture is painted on a <canvas> at load time. Double-click index.html and it runs.

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Playing

Action	Keyboard	Gamepad
Throttle / brake	W S or arrows	RT / LT
Steer	A D or arrows	left stick
Boost	Shift	A / cross
Handbrake (drift)	Space	B / circle
Air pitch / roll	W S / A D while airborne	stick
Restart	R	—

The clock is the whole game. 40.00 s, counting down from the moment the 3-2-1 ends. Run it out and the delivery fails.

Cargo integrity starts at 100 %. Every solid hit and every bad landing knocks a chunk off. Arrive below 50 % and the donations are written off — the run counts as failed even if you beat the clock.

And you can see it happen. The bed is loaded with five crates, and every 15 % of the load you lose, one of them actually leaves — thrown back over the tailgate to bounce and cartwheel away up the road behind you. The top crate goes first, then the pair by the tailgate, then the front pair, so by 25 % the bed is visibly stripped. A number ticking down on a panel is a statistic; a crate tumbling in your mirror is the delivery coming apart.

Boost is earned, not given. Sustained drifts pay out, nitro floats over the streets for you to drive through, and landing a stunt pays the most:

Stunt	Trigger
Flip	≥ 340° of pitch in the air
Barrel Roll	≥ 340° of roll in the air
Big Air	≥ 1.1 s of airtime

Arriving intact is worth something. Getting the whole load across means forty seconds through cross traffic without once getting it wrong, so it pays out rather than just printing a different number on the same card:

Arrival	Bonus	What happens
100 % cargo	+2,500	gold card, PERFECT DELIVERY across the screen, a rising fanfare, and three seconds of gold confetti fired from a ring around the forecourt
≥ 90 % cargo	+1,000	cyan card, PRISTINE LOAD, a shorter fanfare and a second helping of confetti
≥ 50 % cargo	—	the normal handover

Nitro hangs about three metres up rather than being painted on the road, so collecting it is a line you take rather than a stripe you happen to cross — and the three strung out past every barrel-roll lip can only be had in flight.

Badges ride on the world, not just the HUD. A pill sits over the orphanage the whole run with the live distance on it, and slides to the edge of the screen with a pulsing marker when the drop-off is behind you — so the direction home is never a thing you have to go looking for on the radar. Kickers announce themselves about a block and a half out, in their own livery, which makes taking one a decision you commit to early rather than something that happens to you at 150 km/h.

Air costs you nothing. Nothing is touching the tempo in flight, so nothing takes speed off it — you land doing what you left at, and boosting through the air gains up to a ceiling of 209 km/h. Ramps used to charge about 40% of your speed for the privilege, which made the quick line one that ignored every ramp in the city. Now taking one is worth it.

Times, cargo % and stunt score are kept in a top-10 leaderboard in localStorage, on this device only.

The storage keys still carry a .hard suffix. That is history, not a setting: when the menu offered two cities those keys held the 172 m one, which is the only city now, so the board carries straight on from the times already saved under them rather than starting empty.

Under it sits a second board, Full Load, which only takes runs that arrived with cargo integrity at 100%. It keeps its own store rather than filtering the first one: a clean 34 s run would otherwise be pushed off a shared top ten by four scrappy 30 s ones, and the thing the board exists to celebrate would be the first thing to disappear. A full load also gets its own shot at saving, so a careful slow run is never turned away for missing the outright top ten.

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One city

How far apart the streets sit is the one number the whole city is built from — block contents, ramp run-ups, nitro spacing and traffic spans are all derived from that spacing. It is 172 m, which puts the gate and the orphanage 2064 m apart by road: a clean run lands around 39 s against the 40 s window, so only a near-perfect one gets there.

There used to be an easier 152 m city to pick from on the menu. One race is the better answer — every name on the board drove the same town, so the times all mean the same thing.

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The city

A 9 × 9 open grid of intersections, 172 m apart, so a 1376 m square of streets, 28 m of tarmac wide. Past the last junction the city gives way to open country: fields, hedge lines and orchards running several hundred metres out, so the grid ends in a landscape rather than at a border. There are no invisible walls anywhere — drive out there if you like, it only costs you the clock.

The DSCE gate is a block in from one corner and the orphanage a block in from the far one, 2064 m apart by road against a 1460 m straight line. The mint line on the tarmac and on the radar is the suggested route: it staircases through the middle of town, it sticks to the streets, and it is not the fastest way there.

The orphanage end is not a second arch. An arch has to be driven through, which means lining up on it, and after a run spent cutting corners that is the wrong note to end on — you should be able to arrive from any direction and simply be there. So it is marked the way a landing site is: the ground painted with a ringed, chevroned apron, a soft column of light standing over it so you can pick it out over the rooftops, and nothing solid anywhere near it. Hand the crates over and the column turns gold, a shockwave runs out across the forecourt and a DONATIONS DELIVERED board rises out of the middle of it, turned to face whichever way you came in. The result card waits a beat so you actually see it happen.

The 64 city blocks come in six flavours, and most of them can be driven through:

Block	Count	Shortcut
Courtyard	29	four buildings with wide gaps between them, passable on both axes
Solid tower	11	none — go around
Plaza	7	stalls round the edge, paved and open across the diagonal
Alley	6	a single 13 m slot punched clean through
Construction site	6	dirt, scaffolding, material piles and a site hut
Park	5	grass, an off-centre fountain, trees round the rim — open in the middle

Ramps are everywhere, and every one of them is on a street. 79 kickers are scattered across the grid — about one street segment in two gets one, placed at a different distance along the block each time and alternating sides, so there is no long stretch of empty tarmac and no two setups that read the same.

Each one sits in the outer lane, hard against the kerb, which is where the paint already marks a lane off. That is the whole geometry of the thing: the deck is one lane wide, so taking a ramp is a line you commit to rather than something the road funnels you into, and the two inner lanes stay clear for a driver who wants no part of it. Neither gate has a kicker within 70 m, so nothing launches you before you have read the clock.

Kicker	Livery	What it does
Stunt ramp (53)	indigo deck, cyan chevrons and rail lights	straight launch — flip it yourself for the boost
Barrel roll (26)	magenta, and the deck visibly corkscrews	banks you over and throws you into a roll

A barrel-roll kicker is an Asphalt one: the deck is flat at the foot and banked right over at the lip, so it hands you the rotation instead of asking you to start one from nothing in mid-air. The tempo leans with the deck the whole way up it and is already half onto its side at the lip — the roll in the air is the same motion carrying on, not a spin that starts from nothing — and it is metered out to finish exactly one revolution later, eased at the end, so you come down on your wheels. Fighting it on the roll key is what costs you, not forgetting to use it. Take the deck end to end and the roll always has the air it needs — the ramp drops you six and a half metres, which is most of a second by itself. What it refuses is the scrappy entry: clip the foot or slide off the side halfway up and you leave with the bank but no height to pay for turning it, so the truck simply rights itself instead.

Traffic runs the inner lanes. 230 cars — saloons, hatchbacks, vans and pickups, each with its own glasshouse, bumpers, lit lamps and wheels — hold the two lanes either side of the centre line, leaving the kerb lanes to the ramps. That is deliberate: a car driving through a ramp deck looks like a bug even when it is only paint, and it means the lane with the stunts in it is the lane with nothing coming. They lift off for anything filling the lane ahead and get knocked aside if you barge one, so they can never pin you — but they cost cargo and they will break your rhythm. Nothing spawns on the start line or in the drop zone.

Cutting the corners is what buys you the time, and the 40 s window does not leave enough of it to make the trip on the engine alone — the run is really a question of whether you can keep the nitro meter fed. The grass makes you pay for the distance a shortcut saves, and the suggested line costs the most cargo of anything, because it runs you through every junction in town.

The measured bot-run table that used to sit here was taken against the old 45 s / 40 % tuning and no longer describes the game. It needs re-running.

Off-road is slower but never fatal — grass and dirt cost grip and add drag, paving and pavement barely cost anything:

Surface	Grip	Extra drag
Road	1.00	—
Pavement	0.96	0.13
Plaza	0.95	0.11
Roof	0.94	0.13
Dirt	0.84	0.40
Grass	0.77	0.64

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Code

index.html          CDN tag for three.js, canvas, HUD markup, overlays
styles/ui.css       rounded-pill design tokens + all UI layout
src/core.js         MUD namespace, math helpers, keyboard + Gamepad input
src/textures.js     every texture, painted procedurally on a canvas
src/world.js        grid city: streets, blocks, ramps, pads, GPS routing
src/vehicle.js      the tempo: drive, drift, boost, air control, stunts
src/audio.js        WebAudio engine, boost, impact and stunt sounds
src/hud.js          speed, boost arc, cargo, clock, stunt toasts
src/minimap.js      GTA-style circular radar, drawn in 2D
src/markers.js      DOM badges pinned to world positions (drop-off, ramps)
src/leaderboard.js  localStorage top 10 + full-load board
src/game.js         state machine, fixed-timestep loop, lighting, wiring
assets/             vehicle styling reference (not loaded by the game)

Everything hangs off one window.MUD global and loads as plain <script> tags — no ES modules, because modules are blocked on file://.

three.js is pinned to r148 on purpose. r148 is the last release that ships a non-module UMD build, and that build is the only reason the game runs by double-clicking rather than needing a server. Bumping the version breaks file:// unless you also switch to serving the folder.

Under the hood

• Physics is hand-rolled arcade kinematics on a fixed 1/120 s timestep with an accumulator — not a physics engine, because Asphalt-style handling is tuned feel rather than simulation.
• Collision is circle-vs-AABB against a spatial hash of building boxes. Clear the roof height and you pass straight over the top.
• The GPS is a breadth-first search over the 9 × 9 node grid, re-run a few times a second, so it re-routes the moment you leave the suggested line. Its tie-break is memoryless on purpose — anything that depended on how you arrived got reset on every rebuild and collapsed the route onto the rim.
• Traffic is kept out of the static collision hash and tested separately each frame, since it moves. A hit displaces the car, never the tempo: splitting the push between them deadlocks the pair at walking pace.
• Flat surfaces (tarmac, junctions, pavements, grass, paving, dirt) are merged into one mesh per material, which keeps the whole city at a few hundred draw calls.
• Anything built from a pile of small rigid parts — a ramp rig, the tempo itself — goes through Batch, which stamps every part into one buffer and returns one mesh per material. The tempo is about two hundred pieces and none of it is ever off screen; left as separate objects it was two hundred draw calls on every frame of the run, and merged it is thirty-six.
• Nitro and traffic are InstancedMesh, so 186 floating cells and 230 cars with eight detail layers each are ten draw calls between them.

Credits

Vehicle styling is an original build from primitives; assets/vehicle-reference.jpg is the look that was aimed at. No third-party logos, badges or model names are reproduced anywhere in the game.