Before choosing a team, hold B and press right. Your selection will switch sides. Now choose the team you play against and their line up. After choosing the team, hold B and then push LEFT. Now choose your team.

Go to the options screen and highlight fighting. Hold down on the L button and press C-right, C-left, C-left, C-right, C-down, C-up, C-up, C-down, C-left, C-right, C-right, C-right, C-left, C-right, and C-left. You will now fight with everyone you check.

To get more options, go to the Options screen. Press and hold C-down and then press R to access a new menu. To use it, enter one of the codes below.

Change announcer voices: Hold C-Up & press R
Change body size: Hold C-Left & press R
Change head size: Hold C-Down & press R