The classic game of solitaire
Use the mouse to drag and drop cards, placing all the cards in each suit in stacks of ascending rank. Stacks of cards with alternating colors in descending rank can be built in the bottom half of the screen as an intermediate step. Pretty much the same as windows solitaire!
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.