At the options screen, hold down 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 finally Left C. Make sure you held down the L button the whole time when you pressed those buttons. If you did the code correctly, you should get into a fight every 5 to 20 seconds!
Go to the main menu screen and go up to where it says Play Game but don't click yet. Press any of the C buttons and hold it. While holding press start and you will instantly be Wayne Gretzky and the New York Rangers.
On the Options Screen, before you've picked your team, hold down the L button (on top of the controller.) While you're holding down the L button, press Right C, Left C, Left C, Right C, Left C, Left C, Right C, Left C & Left C. When you go to the team selection screen, you should see four "super" teams: Canada, USA, 99'ers and Williams.