Combine a black Mahjong stone with a white Mahjong stone and clear the board before your time is up
Combine a black Mahjong stone with the same white Mahjong stone to remove them from the board. You have 20 minutes to play for the highest score.
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.