Play the game using the mouse to select tiles. Start each level by either selecing the wild card or click the deck carousel (or press space) in the lower left corner.
Look at the value of the current tile and select tiles on the game board with a value one greater or lower than the current tile. Current tiles with a value of 13 can play tiles with a value of 1 and vice-versa.
If there are no more tiles available to play either select a wildcard if available, or click the deck carousel. Wildcards let you can select any tile on the board.