I played this game and really liked it. You click the arrows to slide the pieces. The size of the grid you have to solve and the max number of moves required to solve is preset for each level to determine the difficulty, but the colors of the tiles and their positions after scrambling are random so each time you play level 10, for example, it will be different. So you could replay level 10 and get a different, but similar, experience each time. There are modifiers for tiles that can make the game more challenging/dynamic, for example, early on you encounter tiles in your grid with an X and no color, and these tiles don't move and are skipped over when sliding pieces.