Day Hike

One hiker is missing, last seen at Trail 14, and the poster at the trailhead is the whole briefing. You are the park ranger sent to find them. Lead a search party of up to five up the trail to the crest, where the hiker is waiting, and so is whatever left them there. Then get everyone back down to the road.

Trail 14

From the park's leaflet, as you'd find it in the box at the trailhead.

A day hike of moderate difficulty from the coast road to the crest and back. Allow the day. Carry water and a light. The trail is marked at every fork; please keep to it, for the ground's sake and your own.

Every hike is its own forest: the world is built from a seed, so a party that sets out together walks one world, and a new seed is a new one.

Under the hood

Three layers, one direction of dependency: game/ → net/ → sim/. The simulation is pure TypeScript with zero dependencies, steps at a fixed 60 Hz from a seed, and never imports the renderer, which is what makes the netcode testable headless and a replay bit-identical. A match runs peer to peer over WebRTC; a small signaling server introduces the party and steps out, so the game costs nothing to keep online. Solo play is a host with no peers, the same code path.

Built with TypeScript, Babylon.js 9, Vite, Vitest and WebRTC. The details, from the world's generation to the rendering to the hosting, are in ARCHITECTURE.md and docs/.

Write-ups of the work, with measurements, are on csarko.sh: WebGPU vs WebGL2, photorealistic water, atmosphere and dread shaders, host-authoritative co-op netcode, and 20+ more.

Run it yourself

npm install      # Node >= 22.13
git lfs install  # the models and textures are LFS objects
npm run dev      # signaling server and Vite together, then open http://localhost:5173
npm test         # headless: determinism, movement, collision, the protocol, the world

A desktop launcher for macOS and Windows that loads the site lives in desktop/.

License

GPL-3.0. Use it, study it, change it and share it, and share your changes under the same terms. Third-party models and sounds are credited in CREDITS.md.