Good tips. Here's some more:

1. The Shotgun is the best item in the game period. The pellets travel across the screen and are quite powerful. In the Jungle area, when you get "The dead are restless!" notice, there will be a grave marked ASH (Evil Dead reference!) If you bomb it, there will always be a shotgun there.

2. If you steal from a shopkeeper, they will stop being at the exits when you reach the next world. If a shopkeeper dies, whether you did it or not, they will be at every exit the entire game until you die.

3. If you're going to steal from a shopkeeper, wait until a Freeze Ray appears in their shop. Pick it up, let the shopkeeper get close, then freeze them and bonk them on the head for an instant kill. Then you can take all the items plus the shopkeeper's shotgun!

4. If you sacrifice a living damsel at Kali's altar twice in one playthrough, you will receive the Kapala, which lets you collect blood from killed enemies. When you get enough blood, you get a heart.

I've recently gotten addicted to this game after picking it up at a deep discount via the Sales & Specials Scratch & Match app thingy on XBLA. I had no idea that you could sacrifice stuff on that alter...I thought it was something to avoid destroying less you feel the spidery wrath of the goddess.