Reaxion

The computer system of a nuclear power plant has been damaged by a virus, and you have to debug it before the plant would explode! This means in practice that there is a board consisting of tiles, on which you have to make every tile the same, as in turning either into a colored or uncolored state. You control a cursor, and if you click on a tile, that one and every other neighboring tile around it inverses its state. Each level starts with a different pattern, and there is a time limit too.

Reaxion was originally released for the C64 in 1994 and Amiga in 1995; the original author later ported it to Atari 8bit in 2005. The game was sold commercially by retro sites at release.