Enter these codes at the "Code Entry" menu. You can find it under "Extras".

Effect - Password

1-Hit Dishonor - 54641
Character Concept Gallery - 97831
Double Damage - 34743
Neverending Stealth - 53467
Unlimited Chi - 24463
Unlimited Copper - 23637
Unlimited Health - 94677
Unlock all Treasure Maps - 37437