Super Smash Bros
Earn Captain Falcon
Play as one character all the way through the 1-Player challenge within 15 minutes. After the game's credits, you'll get challenged to a one-on-one duel with Captain Falcon. If you can defeat him, he'll appear in the upper-right of the character roster.
Earn Jigglypuff
Play as one character all the way through the 1-player challenge after earning Captain Falcon. After the credits, Jigglypuff will challenge you. If you win the fight, she'll appear in the lower-right of the character roster.
Earn Luigi
To get Luigi in your roster, you must defeat the Bonus Stage 1 levels for each of the eight original characters, either in Practice or the 1-Player mode. Then Luigi will challenge you to a fight. If you win, he'll appear in the upper-left of the character roster. (Note: To win the fight easier, save one of your better characters for last in completing the Bonus Stage.)
Earn Ness
Start a 1-Player game, set the difficulty to "Normal", and the set amount of lives to three. Choose a character and take him/her through the game without continuing. If you accomplish this challenge, Ness will appear after the credits and challenge you. Defeat him and he'll appear in the lower-left position of the roster.
Earn Mushroom Kingdom
First, defeat the game with the original eight characters on Normal difficulty with three stock. Then enter each Multiplayer stage once.
Earn Sound Test
After earning every character in the game, head into Bonus Stage 1 and 2 and complete each task with all the characters. You'll then be informed that you've earned the Sound Test. Now access the main Options menu to listen to every song, speech, and sound in the game.
Earn Item Switch
Play 100 rounds of Multiplayer to earn the Item Switch menu. Now access the Options menu to choose how often power-ups will appear in Multiplayer mode. You can turn on and off the frequency of each item in the game.