Bomberman 64: The Second Attack cheats and cheat codes for Nintendo 64

Use CPU characters in battle mode
Hold Z and hit A at the battle mode character selection screen.

Unlock Music option
Finish story mode once

Unlock Battle royal mode
Win the gold cup in survival mode

Unlock King and knights mode
Win the gold cup in battle royal mode

Unlock Key trial mode
Win the gold cup in king and knights mode

Unlock Score attack mode
Win the gold cup in key trial mode

Change title screen
Finish the game once