GL – Tris is a Tetris game released in 2004 by Brian Postma. In this game, your main task is to arrange some Tetris pieces in order to clear the screen at the end of the game and get a higher score. This game has poor graphics, even though it is a 3D Tetris game, but it is easy to be played by gamers of all ages, from young to adults. To start the game, press the F1 key and then use the arrow keys to move the Tetris pieces and rotate them in different directions. To drop a colored block, press the down arrow key.