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 neighbouring tile around it inverses its state. Each level starts with a different pattern, and there is a time limit too.

The Amiga version was shareware, and the registered version includes more levels and a level editor, which is now free.