A timed game of Memory, make matches to gain more time, the more time you have left, the higher your score.
Flip cards by clicking on them, Flip two matching cards to clear them. Each match gives you a little more time, If time runs out, game over. Can you get to stage 20?
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.