Originally Posted by BillyBobTwo
OK. I have never played any of the previous ones so I will answer best I can based on just what I know about this one.
Nephilim difficulty is one of three starting options. They can be switched at any time. So Nephilim is the hardest of the base 3, but not that hard.
If you are talking about health items there are 2. One gives you part of your health back, the other gives you all of it. They are bought with Red Orbs and found in missions and you can carry 10 of each. There are also Gold Orbs that you can carry 3 that allow you to die and continue on, not from checkpoint.
There are a LOT of checkpoints. So you can use a Gold Orb if you have one, or just start back at the last checkpoint. Each item and death counts against your total score.
holy waters are pretty much mini nukes that take out most the baddies. not great for style, but gets you through the tough parts later on.