Wario Land 3
Press Start + Select + A + B during game play.
Free Wario Golf play:
Before you enter a Wario Golf game, save the game. Reload the game and enter
the door. If you do badly in Wario Golf, shut the Game Boy Color. Reload the
game and you will be outside the door. Keep repeating this until you win.
Time attack mode:
Successfully complete the game after collecting all 100 treasures.
Extra Golf mini-game course:
Collect each of the eight musical coins in every level, then unlock time attack
mode. Get all seven crayons to unlock a fourth Golf mini-game course between
worlds N and W.