I've had to turn this down to easy
I don't know why, I've played plenty of action games to completion but this one just drove me crazy. My breaking point was the upside-down face boss with his double-dragon arms. I just never seem to have any health items and I wasn't making any progress against him after 9 or 10 attempts so I just said bollocks to it and re-started on easy.
The thing is, being forced to play on easy is kinda souring my experience (I've never
had to drop a games difficulty before) and now I don't really want to play it, I've gone back to the Saboteur instead. Maybe I'll just drop it entirely until I've finished Saboteur and Bioshock 2 and then come back to beating it on Normal.
Oh well, from what I've played so far it's a very cool game.