Intentionally die three times in a row during Chapter 1. Answer "Yes" when Ayane asks "Do you really give up the way of Shinobi?" to unlock the Ninja Dog difficulty setting. Ninga dog allows the game to become acceptebly easier: you start in half way through the level with a new item and every level you get a new item!
Submitted by David Patrick
An easy way to get karma and money! This may only be done in chapters 6, and 7. First of all, your going to need to find a place with a fair amount of Skeleton Warriors, that can respawn by leaving the room, then entering it once again. I highly recomend the "Ritual Room". Ok, first thing you'll want to do is ignore the Skeleton Warriors for now, and hop around and kill ALL other creatures. As soon as your through with that, equip you Lunar. Run to a safe place where you can stand for at least about 5 seconds without getting hit. This should be fairly easy because Skeleton Warriors are EXETREMLY slow. Charge up your Lunar all the way (when you see an explosions around yourself, and then another that means your fully charged) and wait for the Skeleton Warriors to come in range of you ultimate attack. As soon as they get in range, unlease your attack. If you havnt touch them until now, they shouldnt be dead yet. Jump to another safe spot and repeat the process. Each time you kill a Skeleton Warriors it with this strategy it should drop about 1300 essence. You'll be rich!
Submitted by Muffins are yummy