Infinite creation points
Create a player, then go to "Edit Player" at the roster screen. Press Up or Down to choose the player you want to edit. Press Right to get to the speed category. Press A, then press A again.
Self-onside kick
On kick-off onside kick aimed all the way to the left, kick softly, and your own players will pick up the ball, and you will retain possession for another 4 downs!
Special Madden Comment
Play Madden 2002 on a holiday (holiday on your system calendar) and Madden will comment about it. For example, on Thanksgiving he says, "Happy Turkey Day!"
Unlock Team Ecko
Create a team using Create-a-Team editor, and then save the team. Start a game, and at the Team Select screen, press Y to load your custom team. When you return to the Team Seclet screen, press Left, Left and team Ecko will be avaliable.
Infinite creation points...