Definately worth a hack (n slash), though it could have been better. It could have been multiplayer!
Aside from that, the game is mostly fun, if a little simple for a supposedly next gen game. The lack of any really interesting combat mechanics makes kills seem to be the same over and over again, but that could have been forgiven if the game had been split-screen multiplayer, which I've no doubt the PS3 could have handled easily, since there are hundreds involved in the big battle scenes as it is.
Not sure it was worth the high price tag, but definately worth renting, or eventually picking up from a bargain bin!