1080 Avalanche - GameCube

Enter the following at the code screen.

JAS3IKRR	Novice Avalanche Challenge
2AUNIKFS	Hard Avalanche Challenge
EATFIKRM	Expert Avalanche Challenge
9AVVIKNY	Extreme Avalanche Challenge

Extra costumes:
To unlock these costumes, you need to beat Hard mode with these characters:

Ricki Winterborn to get Frosty Winterball
Akari Hayami to get Crystal Hayami
Kemen Vazquez to get Titanium Vazquez
Rob Haywood to get Bones Haywood
Tara Hunter to get Mimi Le Moose

Thanks to Revolution readers 720l33t and Charlie!