You can change your character's outfits by tapping the four C Buttons at the character select screen. Some costume changes are limited to colors, but characters like Pikachu are also available with a hat.
Item Switch Menu
To unlock the Item menu (where players determine weapons and their frequency), play Vs. mode at least 50 times.
Kirby's Power Loss
Everybody knows that Kirby can swallow his opponents and take on some of their powers in this game, but what if you accidentally "ate" a character you didn't want -- and you want to pursue someone else? Simple: Just press the L Button to pull of Kirby's "Hello!" taunt and he will discard whatever power he took on.
To unlock the Mushroom Kingdom beat the game with all eight original characters. This will open up a level that resembles an old-school Super Mario Bros. level.
Play as Captain Falcon
To play as Captain Falcon, you must beat the game on any difficulty in UNDER 20 MINUTES. After that Captain Falcon will challenge you. Once you beat him, you be able to select Captain Falcon as a character.
Play as Jigglypuff
If you want to get the pokemon Jigglelypuff all you have to do is beat the game and then you will face JigglyPuff in a battle. If you beat JigglyPuff you will be able to use her in the game.
Play as Luigi
To play as Luigi, pass the Bonus Practice 1 with at least 8 main characters. When Luigi challenges you, defeat him and he's yours.
Play as Ness
To play as Ness, beat the one-player mode with any character, with the number of starting lives set to 3 and the difficulty set to NORMAL. You must beat the game without continuing.
Have you ever been hit so far you haven't been able to get back into the game to help your buddies? After being hit into the air, tap Z as soon as you hit the ground. When you hit the ground, you will spring up from the ground quickly, and you can be back in the game faster. Also, you can press forward or backward to roll after you have sprung back into play.
You can rotate and view the characters from different angles by entering the character bio section and holding Z. You can use the analog stick to move them around.
To activate the Sound Test, successfully complete Bonus Practice games 1 and 2 with all characters – including the hidden ones. The Test Music option will appear on the Data screen.