Tetris DX - Gameboy Color
Expert mode
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Press Start to pause game play, then press Select. The preview
window will not show the next piece when game play resumes.
Reverse movement
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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
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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
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Press Start + Select + A + B during game play.
Continue game play
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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
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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.