Press L or R before running into the endzone, and your player may do a dance. He must be wide open.
Infinite Create-A-Player Points
Create a player, then go to Edit Player. Select the speed category and then select attributes. When this is done you will have 99 Points maximum in each category.
Season's Greetings
While the GameCube clock is set to December 25, Pat Summerall will say "Season's Greetings" when you begin an exhibition.
Thanksgiving Commentary
Set your GameCube clock to Thanksgiving (11/22) and Madden will talk about it during his commentary.