Metro Rush

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 a browser-playable 3D endless runner called “Metro Rush.” Use a third-person perspective behind and slightly above a generic stylized commuter who automatically runs forward down the center of a modern underground subway station. The camera should be a perspective camera looking along the track/platform corridor, with a dark blue-black subway interior, atmospheric fog, shadows, and slight camera follow to the player’s horizontal movement and jump. The player runs on exactly three lanes at x positions left, center, and right, and smoothly shifts between lanes while the environment streams toward the camera/player. The visible environment should continuously recycle in segments so the run is effectively endless: a wide central runner platform, dark side track beds with bright yellow rails/ties, side walls, ceiling, fluorescent strip lights, cylindrical station pillars, parked subway trains along both side tracks, station signs such as “42 ST” and “DOWNTOWN,” graffiti labels like “RUSH”/“NYC,” and generic transit advertisements. Use procedural built-in geometry and materials so the game is immediately playable without requiring downloaded 3D assets. The visual style is polished low-poly/procedural 3D with bright emissive cyan, yellow, red, green, and purple accents against a dark subway setting.

The player avatar should be a small stylized commuter made from simple geometry: navy coat, bright cyan shirt, yellow tie, skin-colored head and arms, dark hair/visor, dark shoes, and a purple messenger bag with yellow strap. Animate a visible running stride, arm and leg swing, head bob, bag swing, lane-change lean, jump pose, and slide lean. The player’s forward motion is automatic; the objective is to survive as long as possible, build score, collect pickups, and beat the saved high score. Score increases continuously based on running speed, and the HUD should show integer Score, persistent High score, and a Speed multiplier starting at 1.0x. Speed gradually rises from a base speed of about 14.5 to a cap around 31, while spawn gaps shrink over time, making the run harder.

Implement controls exactly as follows, including the intentionally reversed horizontal mapping: keyboard A or Left Arrow changes lanes one direction and D or Right Arrow changes lanes the opposite direction (in the supplied game, A/Left calls the positive lane change and D/Right calls the negative lane change). W, Up Arrow, or Space jumps; S or Down Arrow slides. Also support touch swipes on the canvas: horizontal swipes change lanes with the same reversed left/right mapping, upward swipes jump, and downward swipes slide. On touch devices show four translucent bottom controls: left/right lane buttons plus SLIDE and JUMP. Lane movement should be clamped to the three lanes. Jump uses gravity and a strong upward impulse, and sliding is a short timed low-body pose; jumping and sliding are grounded actions.

Spawn objects ahead of the player in random lanes as the world advances. About half of spawned objects are collectibles: rotating/pulsing transit tokens worth 50 points, coffee cups worth 75 points, and blue transit tickets worth 100 points. Make the coffee cup recognizable with a dark lid, orange sleeve, and small cyan steam accent; make tickets rectangular with a stripe; make tokens glowing gold. Collectibles disappear on contact. Add occasional power-ups represented by bright geometric cores with orbiting rings: Slow Time (purple) reduces world movement to roughly 55% for about 6.5 seconds; Dash Shield (red) lasts about 5.2 seconds and lets the player smash through obstacles, awarding a small bonus rather than ending the run; Magnet (green) lasts about 8 seconds and pulls nearby collectibles toward the player from within a generous radius. Show power-up labels/timers in the top-right HUD as pills, highlighting active powers, and show short toast notifications such as “Time slow!”, “Dash shield!”, “Magnet on!”, and “Incoming train!”.

The remaining spawns are hazards placed in lanes. Include solid full-height blockers: other green-coated commuters holding phones and dark pillars with yellow safety bands. Include low jumpable hazards: purple wheeled luggage with a handle and orange construction barriers with white stripes and a beacon. Include low overhead slide hazards: a yellow hanging sign/barrier with a dark center bar and glowing end blinkers positioned high enough that the player must slide beneath it. Occasionally spawn a large incoming subway train in one lane as a major hazard; model it as a bright subway car with white body, dark lower skirt, red roof stripe, cyan route stripe, windows, doors, and yellow headlights. Contact with any hazard should end the run unless Dash Shield is active; jumping avoids the low luggage/barriers, and sliding avoids the overhead hazard. Use bounding-box style lane/height/depth collision so the three-lane dodge gameplay is clear.

Begin with a dark translucent rounded start menu centered over the station. It should show the title “Metro Rush,” the description about dodging pillars, luggage, barriers, commuters, and incoming trains while collecting tickets, coffee, and tokens, a yellow “Start Run” button, and the control instructions. When Start Run is pressed, play a short approximately 4.2-second procedural intro cutscene before control is enabled: a transit guard with a cap, badge, baton, dark uniform, and glowing accents appears behind/near the commuter, with a side-to-behind cinematic camera move and captions “Security spotted you!” followed by “The guard is closing in — get ready.” Then transition to “GO!” / “Lose the guard in the crowd.” and start the playable run. During this intro, lock normal player controls while the subway segments and initial objects continue moving. After collision, stop the run, save/update the high score, show a centered Game Over menu with the score and high score, the message “Subway got too crowded. Take another run.” and a Restart button, plus a hint that Dash lets the player pass through obstacles.

Use a clean HUD over the full-screen canvas: dark translucent score panel at top-left with Score, High, and Speed; active power pills at top-right; temporary centered toast messages; and intro captions near the bottom center. Keep the station dark but readable using cool ambient/directional lighting, fluorescent emissive strips, glowing pickup/power-up materials, fog, and shadows. Add optional procedural audio after the first user gesture: a fast repeating synth loop around 142 BPM, subtle pink-noise station ambience, short synth blips for jump/slide/collect/power events, and occasional speech-synthesis subway announcements such as “Stand clear of the closing doors,” “Uptown local arriving,” “Please hold on,” or “Express train approaching,” when supported. Ensure the core game remains playable if audio or optional remote visual assets fail to load.