Bonus Madden Card Set
Have the Game Boy Advance games Madden NFL 2005 or Madden NFL 06 in the cartridge slot. Go to 'Madden Cards'. The game will detect the Game Boy Advance game, and you can buy a bonus set of Madden Cards.
High stepping into endzone
While you are running far out in front of everybody and are near the endzone, hold X and your player will high step all the way into the endzone.
Interview questions
In NFL Superstar, choose your answers to interview questions wisely. The answers will affect your personality type and most endorsement companies want a player with a more conservative personality type, such as "Team Leader" or "Professional".
Unstoppable created play
Go to "Features" on the main menu. Go to "Create-A-Play", then "Create New Play". Create an "Offensive Run". Use the "Split Backs" formation. Select "Normal", and when it loads press R button until it is over your Half Back. Change the type to "Runs". Change the play to "Toss L". Make sure that your left wide receiver is blocking, and the play is "Run Blk R". When you test out the play, make sure that you run along the sidelines and juke people out if needed. If you keep doing this, you should have a touchdown in only a matter of plays.
Bonus Madden Card Set...