Tetris on a cube. Tap on a side to rotate the piece; tap from the top to place the piece. If you fill a side, that side disappears, if you create a ring around the cube, the ring disappears. If you do it with same color, bonus! Remember, that the pieces will always appear on the same side, and you have to pick them up by rotating to the top. You can’t fill that side, but it’s wise to start placing as far as possible from that position.