Big Head Mode
At the title screen, enter: C-Up, C-Up, C-Down, C-Down, C-Left, C-Right, C-Left, C-Right, B, A, and then hold down Z and press Start.

Infilitrate the Score Rankings
First start a league and after a game save the league. Next when you can see the score rankings remember those players and press reset. Then go to the option mode trade screen and trade those players with anyone you want. Then press reset(not the one on the machine) and cancel that trade. Then goto the saved league and check the score rankings. It should be changed.

Hidden Teams: Sent in by Jose Pedro from Chilie.
Using the control pad, input: Up, L, Up, L, Down, L, Down, L, Left, R, Right, R, Left, R, Right, R, B, A, and then hold down Z and press start. The announcer will say, "What an incredible comeback!"