Nagano Olympic Hockey '98 

Constant fights 
At the options screen, highlight the "Fighting" selection. Then, hold L and press C-Right, C-Left(2), C-Right, C-Down, C-Up(2), C-Down, C-Left, C-Right(2), C-Left, C-Right, C-Left. If you entered the code correctly, a line of numbers will appear. Now fights will break out constantly.

Multi-player practice mode 
At the title screen, hold A on controllers two, three, and/or four. While those buttons are held, use controller one to highlight "Practice" and press A.

Quick start 
At the main menu, hold B and press Start. Now the game will start at the face-off screen with Modano (Team USA) under your control.

Select opponent 
When playing against the CPU, highlight the desired opponent on the team selection screen and press C-Right(3). If you entered the code correctly, you will hear the sound of a click. Note: This code may not be enabled in Olympic mode.

Invisible players 
Pause the game during the opening face-off and select the replay option. Then, press L or R to cause a player to flash. Press Z while the player is flashing to make him invisible. The entire team can be modified in this manner.

Forfeit game 
Pause the game. Then at the options screen, hold L and press C-Left(9). If you entered the code correctly, digit seven of the "Specials" number will turn to 1. Now when the game is resumed, your team will be losing 1-0 and the clock will be set to 0:00. Note: This code may have to be entered twice to function correctly.

On-fire goal 
Begin a game in arcade mode. Then, approach your opponent's goal at an angle with a full turbo meter. Now press Shoot + Pass + Turbo to see a fire truck appear and score one point.

Push goalie 
Begin a game in arcade mode. Then, approach your opponent's goal directly with a full turbo meter. Now press Shoot + Pass + Turbo to push the goalie into the net and score one point.

Change player appearance 
At the options screen, press C-Down + R, C-Left + R, or C-Up + R. Then, modify the first six bits of a 16-bit register to change the game by pressing:

C-Down + R (head size, alters bits 1 and 2) 
C-Left + R (body size, alters bits 3 and 4) 
C-Up + R (height, alters bits 5 and 6) 
Register What It Does 
100000 Stocky Players 
010000 Stocky Players, Big Heads 
110000 Stocky Players, Small Heads 
001000 Small Players, Small Announcer 
000100 Large Players, Large Announcer 
000010 Crunched Players, Small Announcer 
000001 Elongated Players, Large Announcer 
110110 Large Players, Small Heads, Large Announcer 
010010 Crunched Players, Large Heads, Small Announcer 
010101 Large Players, Large Heads, Large Announcer 
010001 Elongated Players, Large Heads, Large Announcer