Skyline Sprint

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 playable browser game titled “Skyline Sprint,” a third-person 3D endless auto-runner. Use a dark navy futuristic city setting with a forward-facing perspective down a long track. The camera is positioned behind and above the runner at approximately (0, 5.8, 11.5), looking toward the track ahead; it should gently follow horizontal movement. Render with a dark blue background and fog fading the far distance.

The player is a simple stylized blocky humanoid/robot runner centered on a three-lane track. Build the avatar from box meshes: a bright cyan rectangular body, a dark blue glowing visor on its front, and a thin warm yellow stripe around its lower body. The runner automatically moves forward; the player does not steer between lanes and only performs two actions: jump and slide. The avatar starts centered, with three possible obstacle lanes at x = -2, 0, and 2. Animate a subtle side-to-side running wobble while moving.

The track is a broad dark blue rectangular roadway extending far into the scene, with glowing cyan lane divider lines at x=-2 and x=2 and raised pink/red rails along both outer edges. Place a distant skyline of many simple rectangular buildings on both sides of the road, in muted blue, teal, and purple materials, partially obscured by atmospheric fog. Use soft cool hemisphere lighting plus a warm directional light, with modest emissive glow on the visor, lane lines, rails, and obstacles.

Gameplay: after pressing the start button, the runner advances automatically at a starting speed of 15, gradually increasing by about 0.34 per second up to a maximum increase of 9. Track distance continuously increases and is shown as the score. Spawn obstacle patterns ahead around z=-82, approximately every 1.25 seconds, with the interval gradually shortening but never below about 0.72 seconds. Each pattern randomly chooses one of the three lanes and creates either a jump barrier (about 52% chance) or a low-clearance gate. Occasionally, about 22% of the time, also spawn a second block barrier in another lane farther ahead.

A jump barrier is a glowing coral/red solid rectangular block, about 1.5 wide, 1.65 high, and 1.2 deep, positioned on the track so the player must jump over it. A gate is made from two narrow golden vertical posts and a golden horizontal top bar, leaving a low opening underneath; the player must slide under it. Obstacles move toward the runner as the runner advances. At collision range, a block is safe only if the runner’s vertical position is above roughly 2.05; a gate is safe if the player is currently sliding or jumping above roughly 2.55. Otherwise end the run immediately. Remove obstacles after they pass the camera.

Jumping uses Space, ArrowUp, or W, and can also be triggered by a large on-screen JUMP button. Only allow jumping while grounded, applying an upward velocity around 10.5 with gravity around -25. Sliding uses ArrowDown or S, or a large on-screen SLIDE button held via pointer/touch; while sliding, vertically scale the avatar to about 55% height and lower it close to the track. Restore normal height when released. The player cannot act before the run starts or after game over. On collision, stop gameplay and show a centered “Run ended” panel stating the meters covered, with a “Run again” button that resets distance, obstacles, movement, and player state.

HUD/UI should match the visible polished minimalist style: full-screen dark navy canvas; fixed translucent dark glass cards with thin blue borders and rounded corners. At top left show uppercase “SKYLINE SPRINT” in pale blue with the subtitle “Jump high. Slide low. Keep moving.” At top right show “DISTANCE” and a bold white four-digit distance counter starting at “0000.” Before play, center a glass panel with the heading “Skyline Sprint,” explanatory text “An endless auto runner. You only control two moves: jump over barriers and slide under gates.” and a glowing cyan-to-mint “Start running” button. Along the bottom, show a keyboard hint “Keyboard: Space / ↑ jump · ↓ slide” on the left and two prominent touch buttons on the right: cyan/mint JUMP and warm yellow/coral SLIDE. Hide the center panel during play and show it again on game over. Make the layout responsive, with the bottom touch buttons expanding on narrow screens.