Tetris DX

Tetris DX was an enhancement of Nintendo's original Game Boy Tetris, with two added gameplay modes (Ultra, lasting 3 minutes; and Vs. CPU, a match against the computer), a profile/save feature, and color graphics on Game Boy Color and above. In addition, the game had a glitch which lets a player play avoid locks if he holds the direction towards a wall while rotating in the opposite direction with any tetromino except O.