This is an awesome game. Years ago I had the original Tetris on our Mac PowerBook and loved it. The recent incarnation is a poor imitation. Fortunately Doptrix takes the same basic idea and makes it better. In this game you can rotate and flip the board instead of the pieces. Fill up rows to remove them. You can adjust the grid size (6, 8, 10, or 12) and can play a variety of other challenge puzzles based on the same idea. Highly recommended.