House of the Dead Unlockables
After clearing House of the Dead 3, you will unlock the ability to play on Very Easy or Very Hard, along with the ability to use 5 lives and 9 continues.
House of the Dead 2 Unlockables
After clearing House of the Dead 2, you will unlock the ability to play on Very Easy and Very Hard, along with the ability to use 5 lives and 9 continues.
House of the Dead 3 Extreme Mode
Beat both House of the Dead 2 and House of the Dead 3 to unlock the one-player only extreme mode for House of the Dead 3. This mode requires you to hit weak points to kill enemies and allows the use of a blocking attack.
House of the Dead 2 Original Mode Unlockables
After clearing House of the Dead 2 original mode, you will unlock the House of the Dead 2 mini-game. Upon selecting House of the Dead 2 from the main menu next time you play, you will begin a House of the Dead 3 based mini-game with prizes being items for House of the Dead 2 Original Mode. It cannot be played again until you have clear Original Mode again.