Olympic Hockey Nagano'98
Choose Opposing Team
Before you choose your team, hold down B and push right. Your selection should switch sides. Now you can choose the team you play against and their line up (don't push A or you'll be them). After you choose the team, hold B and push LEFT and now you may choose your team.
Credit Goes To: Bryan (Dan ltgman@aol.com) via IGN 64

 Choose Opposing

 Constant Fighting
 Invisible Team
 More Options
Constant Fighting
Highlight FIGHTING on the Options screen, then hold L and press C-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-Left.
A line of numbers will appear at the bottom of the screen if the code was entered correctly. This code has to be entered every period and will cause a fight to break out almost every time you check someone.
Credit Goes To: Pat Kolson (pkolson@hotmail.com) via IGN 64

Invisible Team
To create an invisible team, perform the following.

This cheat may need to be entered more then one time for it to work. Credit Goes To: Alex Waxman via IGN 64

More Options
At the Options screen, hold C-down and press R to access a new menu. To use it, enter one of the codes below.
Change announcer voices: hold C-Up then press R.
Change body size: hold C-left then press R.
Change head size: hold C-down then press R.
Credit Goes To: François Bouthillier (gilles@contact.net) via IGN 64