The following is a list of unlockables a player can obtain in Super Smash Bros.

Unlockable characters

Character How to unlock
Captain Falcon Complete 1P Game in 20 minutes or less.
Jigglypuff Complete 1P Game with any character.
Luigi Complete Bonus 1: Break the Targets with all starter characters.
Ness Complete 1P Game on Normal with three lives or less and no continues.

Unlockable stage

Stage How to unlock
Mushroom Kingdom Beat 1-player mode with all 8 starting characters and play every multiplayer stage once

Modes

Mode How to unlock
Sound Test Complete Bonus 1: Break the Targets and Bonus 2: Board the Platforms with all 12 characters
Item Switch Play 100 rounds of Multiplayer

See also