Diminoes

Diminoes is one of SilliestDuck's browser puzzle games. It installs as a web app and works offline, and it has two parts: a daily puzzle and a campaign of tiny levels that starts with a tutorial.

The board is a five by five grid. Some squares start lit, and beside the board is a set of tetromino pieces, the four-square shapes known from Tetris. Dragging a piece onto the grid flips every square under it, so a lit square goes dark and a dark one lights up. The puzzle is solved when the pieces are placed and every light is off. Undo and restart buttons let you try again.

Each date has its own prepared board, so everyone gets the same one, and the day turns over at 05:00 UTC. A timed trial on a second board runs beside it, and past days of both stay open in the archive. Because a square covered twice ends up as it started, the order of the pieces does not matter, only where each one lands, which makes it a puzzle of covering the lit squares an odd number of times.

It suits players who like short, quiet spatial puzzles such as Lights Out or polyomino packing, and want one small board a day.