Wario Ware Inc. Mega Party Game$ cheats and cheat codes for Gamecube

Unlock Sound test in the option menu:
Play in all multi-player mode

Re-play any mini-game:
To re-play any mini game, you have to unlock the final door in single player 
mode. To unlock this door, you have to collect all roses from all the mini-
games in practice mode. Once the door is unlocked, use the door to re-play 
any game.

Select the "Album" option and pick the All-Stars Book in single player mode 
to get access to all mini-games.

Unlock extra options:
If you finish the games from the first door you can access to the following 
hidden options:
Thrilling Mode
Movies
Mixed Genres Game
Hard Mode
Character Descriptions

Time attack mode:
Play in single palyer mode and reach minimum 30 points on the All Mixed Up 
stage to unlock the hidden "Time Attack" option in single-player.