Tetris Online. Tetra Tower. Original game where you keep two games of Tetris active at the same time. The Tetris figures will be generated in the upper part of the screen and will descend little by little on the game board. Some mice are waiting downstairs to eliminate the pieces that are falling and preventing you from building a wall with them. Toggle the game board with the SHIFT key. to avoid mice. Accumulate points by keeping the Tetris game active.