Cubetrix 3D is a new iPhone game featuring 3D puzzle mechanics that involve clearing the board presented as quickly as possible. The task is accomplished by moving a block around the board and sliding it in where you can. After a little while of playing, it will become second nature to figure out where exactly to move your blocks to accomplish matches and combos.
I could see this game becoming pretty addictive much like Tetris from the past, looking to slide blocks where they need to go for hours on end. I have attached a video put together by the developers to show how to play the game: