ParityNinefold Walk
One small step. Nine numbers in harmony.
How to find harmony
Move with arrow keys, WASD, the direction buttons, or click a neighboring square. Every arrival changes that square by its printed sign: +1 on pale tiles, −1 on dark tiles. The starting square is already selected and unchanged. Edges do not wrap.
Make all nine numbers equal to finish. A low number may need several visits, and reaching it can change other tiles along the way. No timer or move limit. Undo with Z, restart with R. All 100 original studies are available; dark tiles begin at study 51.
Nudge gives the next move on a known solution. If you leave that route, undo or restart to recover it. Completion stays on this device when browser storage is available.