OK, beat GoW in a few days, and decided to try out the challenges. The first one was easy, but the second one is really pissing me off. The flame guards all jump around like rabbits on crack, and don't even slow down when they land, but Kratos moves slower than a mentally handicapped amputee with MS (no offense to handicapped people). His recovery time from a super punch SUCKS! These kind of games need to come with a high blood pressure warning.
The game itself was awesome, but I hate the challenges. You have to be an ultra hardcore game nerd to master the moves to make it through. There is no motivation for the casual gamer (like myself) to try and make it through the challenges.