Wario World Cheat Codes for Gamecube

Unlock Trial Version 2: Heads Up
Collect all eight treasures in Horror Manor.

Unlock Trial Version 3: Gold Digger
Collect all eight treasures in Shivering Mountains.

Unlock Trial Version 4: Lickety-Split
Collect all eight treasures in Mirror Mansion.

Unlock Selected 1: Dodge Balls
Collect all eight treasures in Greenhorn Ruins.

Unlock Selected 2: UFO Assist
Collect all eight treasures in Wonky Circus.

Unlock Selected 3: Jumpin' Rope
Collect all eight treasures in Beanstalk Way.

Unlock Selected 4: Munch a Bunch
Collect all eight treasures in Pecan Sands.

Unlock Trial Version 1: Wario Whirled
Collect all eight treasures in Greenhorn Forest.

Earn the Best Castle
Find all 40 Spritelings before beating the final boss to get the best castle (and best ending).

Infinite Coins
When fighting DinoMighty, grab her tail and wait until she raises it above her head. Perfom a Ground Pound (A + R Button). She'll drop a lot of coins. This stuns, but does not damage her. Repeat as often as you like to get an inifinite number of coins.

Get Best Castle
Get all 40 spritelings before defeating the final boss.