I just got the game a few days ago and have been doing my first playthrough on Hard, great game! I didn't have much trouble disposing of regular guys through most of the game, up until I got to the guys with spikey shields, ever since then even the regular guys have been hard to bring down. Boss fights have been a real pain though, especially Bone Cleaver round 2 and that Sand Dragon. I just got to Graven today then immediately quit without even trying to fight him, decided I needed to take a break so I stopped and watched the Conan movie and had a snack! LOL.
I'll try and fight him soon though. I've learned that patience is the key to the boss fights in this game, learn their moves and run in for a few hits then run out. It's all about avoidance because if you get hit on Hard difficulty it REALLY hurts. I died like 40 times fighting that stupid Sand Dragon.
http://www.youtube.com/user/AnotherSchmoe