A minimal city-collab game skeleton: one mechanic, one return state, readable feedback, and hooks for art/music/code additions. Replace placeholder draw functions; physics stays the same.
1. Move Runner A into the HANDOFF ZONE.
2. Press H to pass the baton. A crumb trail appears.
3. Guide Runner B back to the RETURN STATE (lit hearth).
4. Then carry the baton to the GOAL.
Press Space to begin.