Extra lives:
Press Start to pause game play, then press Select(16). If done correctly, a blinking square will appear around the last digit of the number of your remaining lives. Hold A + B and then press Left, Up to change the number.

In-game reset:
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.

Hint: Finding destinations easily:
Once a level has been completed, if an orange ball spins around a location, you should go there first. If it does not do that, go to the temple.

Hint: Defeat final Boss:
When reach the final Boss, he will try to grab you. High-jump to his nose, out of the way so he cannot kill you. When he throws a fist at you, jump up and stomp it. Then, throw it at his nose. Do this four times to defeat him.