Change Game Speed - At the main/mode select menu, hold the right shoulder button on the Classic Controller and push up or down on the D-Pad to change the game speed. If you push down you should see 3 stars and the color of the Street Fighter II logo will change. There are 3 speeds.

Different Color Outfits! - To get diffirent color outfits for the characters use different buttons to select them.

Edit buttons right before a fight - To edit what button does what right before a fight, simply hold select sometime before the versus screen appears, and do whatever you would normally do, until the edit screen appears. This should work in any mode, and in versus mode you can even select if either player should be CPU, or human.

Reach M. Bison(Vega) without fighting CPU - Select Arcade Mode normally. When you start your fight press START on the controller 2. Then select for the second player the same figther the CPU was using and beat it. You will see yourself in the second fight! Repeat this until you find M. Bison(Vega) and fight for your life!

Select the 8th outfit - When you select your fighter, press and hold all 3 punches or all 3 kicks until the outfit changes color.

Use Up to 8 of Each Fighter in Group Battle - Group Battle usually limits you to two instances of each fighter, but this code increases that number to eight.

From the Game Start screen, enter Group Battle mode. Then, using the second controller, alternately and repeatedly tap L and R until Vega laughs. Choose Match Play or Elimination from the menu. You and your opponent will now be able to use up to eight instances of each fighter.

View Character Profiles - When you start the game wait for the first profile and hold:
L+R on 2P.