Super Smash Bros.
Cheats submitted by: airfiggy

Alternate Costumes:
 Highlight a character, and press any of the four C-buttons to use an alternate outfit Item Switch To get the Item Switch, which allows you to alter all item related aspects of the game in versus mode, simply play 50 VS. mode matches of any length. Sound Test 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.

 Unlock Captain Falcon:
Beat the 1-Player game with any character on any difficulty in under 20 minutes. You will then fight Captain Falcon; if you win, you can play as Captain Falcon.
 
Unlock Jigglypuff:
 Beat the 1-Player game with any character on any difficulty. You will then fight Jigglypuff; if you win, you can now play as Jigglypuff.

Unlock Luigi:
 Beat Bonus Practice 1 with all 8 of the original characters. This can be done either in practice or in the actual 1-player game.

Unlock Ness:
 Beat the 1-Player game with any character on Normal difficulty with 3 lives, without continuing. You will then fight Ness; if you win, you will be able to play as Ness.

Unlock Mushroom Kingdom:
You must first beat the game with the original 8 characters on normal mode and then play every multiplayer stage at least once.

Borrow a life in team multiplayer matches:
 If you are playing in a team multiplayer match and you lose all of your lives, simply press A, B, Z and START, and you will take one of your partner's lives as long as they have at least one in stock.