I saw it tonight, and I didn't think it was too overtly gory. I'm not saying that it wasn't, I'm just saying that's probably what would have happened. The closest thing I can relate it to is the gore in the movies Event Horizon and Final Destination 2. Gory, but not so much that it made me want to leave. Lot's of blood though.
And as for the creative license that Setekh mentioned, almost all of it was used in relation to Satan. So pretty much if you saw Satan on screen, you saw something that wasn't recorded.
I heard someone say something about the Simon of Cyrene part wasn't completely true either, but whatever.