Warning: this game is slightly addictive




Tapping a window switches its light on or off. Due to a bad case of mad wiring, it also turns the lights on or off in the windows next to it: right, left, above and below.
If you move the mouse over the four-window house, you see what happens when you tap the topleft window. If you move it over the nine-window house, you see the pattern that results when you tap the leftmost window on the third floor.
You want to save power by turning all the lights off. When there are four, nine or even sixteen windows, it is not very difficult. The three houses on the bottom row are a tougher puzzle.
I do guarantee that all the levels can be solved.
There are three versions of the game: for the iPad, the iPhone and the Macintosh desktop.
The iPad and iPhone versions work only on iOS up to 11. They do not work on iOS12. Click here to see them in the iTunes store, where you can buy them for $0.99 and download them to your iPad.
The free Macintosh desktop version should be available soon.