Brian The Brain and Space world
Enter the character selection screen, select "Load" then enter "BRAINSALAD" as a name to unlock Brian The Brain and Space world. Alternately, win Smack Attack, Gate Relay, and Flag Relay in all three levels of the Space world.

Count Earl and Transylvania world
Enter the character selection screen, select "Load" then enter "COUNTDEAD" as a name to unlock Count Earl and Transylvania world. Alternately, win Smack Attack, Gate Relay, and Flag Relay in all three levels of the Transylvania world.

T. Wrecks and Jungle world
Enter the character selection screen, select "Load" then enter "TWRECKSPAD" as a name to unlock T. Wrecks and Jungle world. Alternately, win Smack Attack, Gate Relay, and Flag Relay in all three levels of the Jungle world.

Whack Angus and Desert world
Enter the character selection screen, select "Load" then enter "WHACKFAD" as a name to unlock Whack Angus and Desert world. Alternately, unlock all modes (Smack Attack, Flag Rally, Gate Relay), then win all three levels in the Desert world in each one (total of nine).

Melee weapons
Enter the character selection screen, select "Load" then enter "MELEEDEATH" as a name.

Hazard weapons
Enter the character selection screen, select "Load" then enter "HAZARDOUS" as a name.

Personal weapons
Enter the character selection screen, select "Load" then enter "UNIQUEWPNS" as a name.

Ranged weapons
Enter the character selection screen, select "Load", then enter "GUNSMOKE!" as a name.

Movement power-ups
Enter the character selection screen, select "Load", then enter "MOVEITNOW" as a name.

Pen and ink graphics
Enter the character selection screen, select "Load" then enter "PENCILS" as a name.

All FMV sequences
Enter the character selection screen, select "Load", then enter "MULTIPLEX!" as a name.

Big head mode
While playing a game, hold L + R + Up.

Additional FMV sequences
Successfully complete Smack Attack, Gate Relay, and Flag Relay with each character to unlock additional FMV sequences.