After scoring a goal you can make some various sounds that are heard after goals. When the instant replay starts, hit Z to hear different sounds. Keep hitting it until you hear the sound you like and hold the button. This causes your opponents rumble pak to rumble continuously.
Enter these codes on the password screen.
BIGBIG -- Big players
BRAINY -- Big heads
FAST -- Faster gameplay
FASTER -- Even faster gameplay
FLASH -- Makes cameras flash
FREEEA -- Enables 2 new teams, EA Blades and EA Storm
PULLED -- No goalies
VICTORY -- View ending sequence
CHECK -- Check harder than usual