Skyline Run

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 portrait-friendly 3D endless runner called “Skyline Run.” Use a third-person perspective behind and slightly above a humanoid adventurer running forward on a three-lane road. The player stays near the camera while the road, obstacles, pickups, and scenery move toward the player, producing forward motion. Use a perspective camera around position (0, 5, 8), looking ahead down the track; smoothly follow the player’s horizontal lane movement and vertical jump. Render with shadows, a directional sun, and soft hemisphere lighting.

Gameplay: the track has three lanes at x positions approximately -2.2, 0, and 2.2. The character automatically runs forward, starting at speed 12 and gradually accelerating by about 0.25 per second. Move one lane left or right with A/D or Left/Right arrows; lane changes smoothly interpolate rather than teleport. Jump with Space, Up arrow, or W: only while grounded, launch upward with vertical velocity 9 and gravity about 26. Slide with S or Down arrow while grounded for 0.6 seconds; play a roll animation during the slide, otherwise play the run animation. Also support mobile touch: swipe horizontally to change lanes, swipe up to jump, swipe down to slide, plus on-screen left/right/down/up buttons on coarse-pointer devices.

Procedurally spawn content ahead around z=-110 and recycle/cull it as it passes z=12. Most spawns are either a single obstacle (55%), a row of four coins (20%), a magnet pickup (5%), or an obstacle plus a coin row offset behind it (20%). Obstacles randomly occupy one of the three lanes. A normal block is a brown box about 1.8 wide, 1.2 high, and 1.2 deep, centered at y=0.6; it must be jumped over, and colliding while the player’s bottom is below 1.2 ends the run. An overhead bar is a brown horizontal box about 2.4 wide, 0.5 high, and 0.8 deep, centered at y=1.6; it must be slid under, and colliding while the player’s top is above 1.35 ends the run. Use simple proximity collision checks matching the lane and forward distance. There are no lives or health points: one failed obstacle collision immediately causes Game Over.

Coins are gold, slightly emissive metallic cylinders rotated to appear as vertical spinning coins, placed in a straight line of four at one lane, y=0.7, spaced 2 units along the track. Collecting one within roughly 1 unit forward and 1.1 units sideways adds 25 points, provided the player is not too high (jump y less than 1.6). The score also increases continuously with distance at roughly 2 points per unit traveled. A rare red horseshoe-shaped magnet pickup appears in a lane at y=1.2. Collecting it activates an 8-second magnet effect, shown beside the score as a magnet icon and remaining seconds; while active, nearby coins within radius 9 are pulled toward the player and can be collected.

Build a repeating road from straight city road tile geometry, with twelve recycled segments each about 10 units long, spanning the three-lane track. Add broad ground/side planes beyond the road. Place decorative scenery off both sides of the track at each spawn: trees in the first world, cacti in the desert, skyscraper-like pillars in the night city, and simple ice cones in the frozen world. Use appropriate loaded or equivalent low-poly 3D props, with shadows.

There are four cycling worlds, each lasting 700 units of progress. Cycle through them repeatedly: (1) “Sunny Fields,” bright blue sky/fog, green ground, darker green sides, brown obstacles, and trees; (2) “Dusty Desert,” warm yellow sky/fog, ochre ground, darker tan sides, gray-brown obstacles, and cacti; (3) “Neon Night,” very dark blue-purple sky/fog, dark slate ground and sides, pale gray-blue obstacles, and distant skyscraper pillars; (4) “Frozen Pass,” pale blue/white sky and fog, nearly white ground, blue-gray sides and obstacles, and ice cone decorations. Update the top-right label as “Level 1: Sunny Fields,” etc.; after level 4, wrap back to level 1. The HUD score is at the top left in bold white text with a dark shadow, and the current level name is at the top right.

Start with an overlay covering the scene using a translucent black background. Center a large white “Skyline Run” title, followed by “Jump (Space/↑) · Slide (S/↓) · Move (A/D or ←/→)” and “Survive through every world!”, with a rounded orange START button. On start, reset score, speed, level, player lane, jump, pickups, and obstacles, then hide the overlay. On collision, stop the game and show the same overlay with “Game Over,” “Score: [whole number] · Reached Level [number],” and a RETRY button. Keep the visual style clean, colorful, low-poly/asset-based 3D with strong soft shadows and a simple arcade presentation. On touch devices, show translucent bottom controls: left/right buttons on the lower left and slide/jump buttons on the lower right.