In-game reset
Press [A] + [B] + [Start] + [Select]
during game play to reset most Game Boy games.
Alternately, hold [Right] + [B] + [A] and press
[Start].
Hidden Game Boy printer message and picture
Hold the "Feed" button on the Game Boy printer.
Release the button after an image begins to print on the paper.
A test message featuring Mario saying "Hello" to a Game
Boy Printer.