Secret Battle Levels (Import Version):

If you have the import version of Hudson's Bomberman
64, you can find some cool hidden battle levels.
 
You need the Hudson JoyCard 64 controller for this to
work. Go to the title screen, put the "Slow Switch" 
on position Hu and wait five seconds. You should now
hear a sound that confirms that the trick worked. 
Choose Battle Mode and you can access four new secret
stages