300 humans spawn across a dark map scattered with random buildings. A single Patient Zero shambles out from the center. Agents use weighted steering forces (flee, seek, wander, cohesion, separation) to move each frame, with a spatial grid keeping neighbor lookups fast.
When a zombie gets within bite range of a human, that human becomes infected — visibly pulsating orange-to-red — and after 5–15 seconds turns into one of three zombie variants:
A day/night cycle shifts every 30 s. At night a blue overlay drops, zombies speed up 1.4×, and the ambient drone deepens. Buildings block movement and create chokepoints where survivors cluster — then get cornered.
| Click canvas | Drop a new zombie |
| Space | Pause / resume |
| H | Toggle heatmap |
| Speed slider | 0.25× — 3× speed |