Downhill Bike Game 3D Threejs Code

Build a complete first-person downhill bike game that runs in any browser. This prompt is a full blueprint: steep drops, rolling crests, curves, giant kickers, front and back flips, perfect-landing bonuses, 6 levels with medals and awards, AI rivals, slow-motion crash replays, unlockable cameras and controls, and music that grows each level. Outputs one HTML file with Three.js. Change 3 values, run it, then play the free demo to see the result.