After beating the game with certain criteria, new modes and weapons shall be unlocked.

Unlockable	How to unlock
Hard Mode	Beat Normal Mode.
Normal Mode	Beat Easy Mode.
Unlock Cleavers	Beat Hard Mode in under 60 minutes.
Unlock Katana	Beat Normal Mode in under 45 minutes.
Unlock Mace	Beat Easy Mode in under 30 minutes.
Unlock New Background	Beat Super Hard Mode.
Very Hard Mode	Beat Hard Mode.