Highlight a character, and press any of the four C-buttons to use an alternate outfit
If you are playing in a team multiplayer match and you lose all of your lives, simply press START, and you will take one of your partner's lives as long as they have at least one in stock.
To get the Item Switch, which allows you to alter all item related aspects of the game in versus mode, simply play 100 VS. mode matches of any length.
You must first beat the game with the original 8 characters and then play every multiplayer stage atleast once.
To gain access to the sound test menu, complete bonuses one and two with all 12 characters. The option will then appear under the data menu.