Wario Land 3

In-game reset:
Press Start + Select + A + B during game play.
Information in this section was contributed by Brad8911.

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.
Information in this section was contributed by Steven Mettler.

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.

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.
Information in this section was contributed by Steven Mettler.

Hint: Defeating the "rat" Boss:
Use the following trick to defeat the Boss that looks like a rat. Avoid the things that he fires and avoid the blue box. When the box opens, a little man will come out. Press B at it and try to hit the Boss. Do this three times and you should defeat him.
Information in this section was contributed by Eric Manners.

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.
Information in this section was contributed by gartenfreude.