Tetris DX
Expert mode:
Press Start to pause game play, then press Select. The preview window will
not show the next piece when game play resumes.
Reverse movement:
Hold Left or Right while any piece except a straight bar or block is
descending until it is against the wall. Then, keep holding Left or Right
and rapidly tap A.
Alternate screens:
Allow the game to remain at the main screen until demonstration mode begins.
Press Select to display a screen featuring swimming fish. Press A to return
to the next part of demonstration mode, then press A again to display a
screen with confetti and the Nintendo logo. Press B to return to the next
part of demonstration mode, then press B. Eventually a screen featuring a
blackboard will appear.
In-game reset:
Press Start + Select + A + B during game play.
Continue game play:
Press Start to pause game play in single player mode, then turn off the Game
Boy. A continue screen will appear when the Game Boy is turned on again.
Screensaver:
Remain idle at the main menu for about 20 seconds. A demo game will begin.
Press A and remain idle for another 20 seconds. Fish will appear. If you
repeat these steps, flying triangles will appear.