How to play
- Select a cell to toggle it and its neighboring cells.
- Observe the exact pattern changed by each move.
- Clear every light, using restart when an experiment leaves an unhelpful state.
What this game practices
A strong finite-state logic puzzle that rewards systematic experiments. Trial and error is possible, so asking players to explain a repeatable strategy adds educational value.
How we checked it
Open-source HTML5 game reviewed in the local coolmath build for startup, primary controls, restart flow, narrow-screen fit, console errors, failed requests, and third-party network activity. Upstream telemetry is disabled in this self-hosted copy.
Open-source license and attribution
This self-hosted game is adapted from Web Games by mashukui and distributed under the MIT License. coolmath disabled upstream telemetry and records its local changes in the open-source notices.
Reviewed by coolmath Editorial Team · Updated 2026-10-09