Kirby's Dream Land [GB]
Press Down + Select + B at the title screen. Options for the number of lives, sound test, and other selections will be accessible.
Press Up + Select + A at the title screen. A special game with additional enemies and a new ending will begin.
Hold Up + A + Select when the word "Start" appears at the title screen.
Any time during the game pause the screen and wait a few seconds. Kirby will dance around on the paused screen.