Flip

Light every square at the same time. Each click flips the chosen square and its group: lit squares go dark and dark squares light up. The little diagram shows the group relative to its filled centre square. On and Off labels also identify the lights.

Crosses flip the square and its immediate neighbours. Random gives each square a different shape, which may reach farther. Focus a square to read every row and column in its group below the board.

Show solution adds outlined ↻ marks. Flip each marked square once to finish. Clicking an unmarked square adds a mark because that click must be reversed. Games played with the solver do not count as wins. Undo restores the previous lights and marks; Restart returns to the same initial puzzle.