You have to clear the game field by pressing the cards on the field, the number of which is more or less by 1 than the desk card at the bottom.
You can place a King of Two over an Ace. If there are no moves, press the desk to get a new card. Bonus points are added for chain length and playing speed. Every two levels you get a new civilization, pictures and card skins. It includes XI-ART Tournaments support.