Tetris x 4!
Blocks falling in one direction is bad enough…when gravity is constantly changing in 4 directions, you've got quite a task on your hands. Match colored blocks (4 or more) to keep the board clear, and your entrances open. But be careful...you have got to keep up with gravity! Get big points by disconnecting blocks from the central cluster, but don't let any of your 4 entrance points get Blocked!