Nightmare mode
Successfully complete the game to unlock the “Nightmare Mode” option at the Special Features screen.
Test sound
While playing a game, press Left(2), [b] or Right(2), [b].
Alternate Hunter mode
Successfully complete the game with any character to unlock the “Alternate Hunter Mode” option at the Special Features screen. This gives the four playable characters different costumes.
Alternate ending sequence
Save at least fifty innocents before returning to the train to unlock the good ending.
Hidden power-up in Catacombs
When you enter the room with the two sisters/innocents, defeat all the enemies but do not leave. Search the walls in that room and find the spot where the wall is cracked. Attack it with any weapon. It will eventually collapse. Inside are some special weapons and the permanent strength power-up.
Defeating the last Boss
As any character, grab the machine gun at the lower left of the screen. Use any weapon to hurt the Boss. When he goes to recharge, run to the big window in the room and unload your Uzi, Shotgun, Chainsaw, or other weapon into it until it breaks open and the Boss dies. You can pretty much ignore him when he returns from getting charged, since you will be standing on a Health Glyph while destroying the window. Vampire and sunlight equals death. When you get to the last Boss, do not free the three locked up innocents unless you have low remaining lives. Freeing them will make the Boss have two more images of himself, creating three Bosses, but only one will be real.
Catacomb cracks
In the catacombs, if you do not see the crack, slice at the wall that points north from the screen. It should give off white puffs when attacking the correct wall.