Invisible Players: Sent in by PBCHOSER
To have invisible players go to Replay and when the people are flashing press and hold Z.

Thanks to Nicholas from Dallas Texas for sending in these codes!
For non-stop fighting go to any options screen and type in this code: Hold the L button, and push the following buttons right c, left c, left c, right c, down c, up c, up c, down c, left c, right c, right c, left c, right c, and then left c, you should get in a fight every 5-20 seconds.

To get some more teams like USA and the 99'ers, put in this code in the first options screen. Hold the L and press, >C, C, C, At any options screen press Z and an advertisement will scroll across the bottom of the screen.