Dirtbike Dash

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create “Dirtbike Dash,” a browser-based endless 3D dirtbike runner viewed from a third-person follow camera behind and slightly above the bike. The player continuously travels forward along an endless-feeling dark cyber-night dirt track; the goal is to go as far as possible, with distance in meters-ish as the score. Use a Three.js-style low-poly/proxy 3D presentation with a dark blue-purple environment, subtle emissive cyan accents, fog, shadows, distant faceted cone-like mountains, and a large dark sky dome. The track is about 20 units wide, procedurally rolling beneath the player: combine forward sine-wave hills with smaller rut undulations across the width and a slight downward crown toward the edges. Keep the terrain dynamically updated as the player advances so it appears endless, with dark purple-brown dirt and a subtle blue emissive glow.

Build the bike as a simple visible proxy model centered near the bottom of the view: a dark metallic rectangular frame, orange accent seat and handlebar, angled front fork, and two black torus wheels aligned as a dirtbike. Make the wheels rotate with speed. Tilt/pitch the bike according to terrain slope and lean it while steering. Follow it with a smooth camera that looks toward a point ahead of the bike; camera position is behind and elevated, with mild lateral follow sway. When Cyber Tuck is active, lower the camera slightly and closer, and show a cyan emissive rectangular trail behind the bike.

Controls and movement: W or Up Arrow accelerates; S or Down Arrow brakes; A or Left Arrow steers left; D or Right Arrow steers right; Space jumps only while grounded; Left or Right Shift activates Cyber Tuck. Start at speed 9 and apply continuous drag, with throttle acceleration and braking. Clamp ordinary top speed to 34 and Cyber Tuck top speed to 42; Cyber Tuck should reduce drag, increase acceleration/top speed, but reduce steering authority. Steering moves the bike laterally while clamping it within the track. Being near the outer edge causes a strong speed penalty. Apply gravity, grounded collision against the generated terrain, small automatic pops over steep slopes/bumps, and a stronger clean Space jump. The bike should visibly leave the ground during jumps and land back on the terrain.

Place randomly generated hazards far ahead along the route, at irregular intervals roughly 22–77 distance units apart. Use simple gray 1.2-unit cubes representing crates/rocks, randomly labeled internally as crate or rock but visually using the same gray obstacle material. Position each hazard on the terrain and hide it when outside the active camera/world range. If the bike reaches an obstacle’s distance, overlaps it laterally, and is low enough to hit it, crash.

Also generate a sequence of police-car hazards that activate as the player approaches their milestone distances (first around distance 140, then additional cars every roughly 120–240 units). Each active cop begins behind the player and chases forward with its own boosted speed, slight side-to-side lane wiggle, and position constrained to the track. Model each as a simple dark navy low-poly car with a rectangular body, glassy cabin, light bumper, block wheels, and a roof siren bar. Add alternating red and blue flashing point lights. A cop can ram the bike on overlap; when close behind, it also creates pressure and slightly reduces bike speed unless the player is Cyber Tucking. Do not add collectibles, boosts, tricks, multiple biomes, or articulated suspension.

Crash behavior: on collision with a crate/rock or cop, stop normal gameplay, mark the bike crashed, show a dramatic leaned-over/drifting camera/bike pose, and display “Crashed — press R to restart.” Press R after a crash to reset distance, speed, bike position, hazards, cops, and the normal status message. Distance advances by current speed and the on-screen score is the floored distance. Display speed as the floored speed converted to km/h (speed units multiplied by 3.6).

HUD: overlay a compact fixed UI in the upper-left over the 3D scene. Show rounded translucent black pills with thin subtle borders for “Distance” and its number, “Speed” and its km/h value, plus a status/control pill. The initial status should communicate “W/↑ throttle, A/D steer, Space jump, Shift = Cyber Tuck” (the source layout may abbreviate this on first load). Beneath it show a small hint, initially “Click once to enable audio.” Make the UI light gray/white with a soft text shadow and make the status pill red-tinted with a danger border after crashing. Keep the visual style restrained and dark, matching the attached initial view’s minimal HUD over a nearly black/dark-blue background.

Add lightweight synthesized audio using Tone.js or an equivalent browser synth, only after the first click or key press enables audio. Use a short triangle synth note for reset/UI and jump feedback, and a brief brown-noise/synth crash sound on collision. Update the hint to “Audio on.” after activation. Ensure the experience is playable immediately with no title screen, with responsive full-window rendering, resize handling, fog, ambient hemisphere lighting, a directional shadow-casting light, and smooth animation capped to a stable timestep.