Remix: FLY SF

Build a small, playable browser game inspired by "FLY SF" (Action, Adventure, Simulation).
Concept: Fly, parachute, drive, run, and jetpack with friends through ultra-HD photorealistic 3D scans of San Francisco.
Tone/hook (from the game's own page): Fly SF is paused. Fly anywhere on Earth in the classic game at flyover.gg.
Tech: use Three.js; keep it to a single page that loads instantly with no login or install.
Controls: touch controls (tap/drag) that work on a phone plus keyboard and mouse on desktop, shown on a short how-to-play screen.
Multiplayer: the original is listed as multiplayer. Start with a local or bot opponent, then add online play (e.g. WebSockets) once the core loop is fun.
Steps: 1) get the core mechanic playable with placeholder shapes, 2) add win/lose conditions and restart, 3) polish feel, visuals and sound, 4) add your own twist (setting, character or one new rule).
Make it your own: don't copy the original's name, art, text or code.