Constant fights:

Highlight the "Fighting" selection at the options screen. 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. A line of numbers will appear to
confirm correct code entry. A fight will break out at regular intervals
during the current period. 

Multi-player practice mode:

Hold A on controllers two, three, and/or four at the title screen. While
those buttons are held, use controller one to highlight "Practice" and
press
A. 

Quick start:

Hold B and press Start at the main menu. 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). The sound of a click will confirm
correct code entry. Note: This code may not be enabled in Olympic mode. 

Forfeit game:

Press Start to pause game play. Then hold L and press C-Left(9) at the
options screen. Digit seven of the "Specials" number will turn to 1 to
confirm correct code entry. When game play 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 game play in arcade mode. Approach your opponent's goal at an
angle with a full turbo meter. Press Shoot + Pass + Turbo to see a fire
truck appear. 

Push goalie:

Begin game play in arcade mode. Approach your opponent's goal directly
with a full turbo meter. Press Shoot + Pass + Turbo to push the goalie
into the net and score one point. 

Change player appearance:

Press C-Down + R, C-Left + R or C-Up + R at the options screen. Modify
the first six bits of a 16-bit register to change the game be pressing:

 C-Down + R (head size, alters bits 1 and 2)
 C-Left + R (body size, alters bits 3 and 4)
 C-Up + R (announcer's voice, alters bits 5 and 6) 

Register:             Effect:
 
 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