Make an original third-person 3D game that runs in the browser with Three.js, in one web page. The game: a small fox runs across floating sky islands, collecting glowing seeds before a storm arrives. Arrow keys or WASD to move, space to jump, and the camera follows behind the fox. Three islands linked by moving platforms, a 90-second timer, a score, and win and game-over screens. Make all the art in code, with no image or video models. It should feel good to play the moment it loads. Test it in a headless browser before you finish.