Just finished the single player on Hard. Shame this is getting swept under the rug, it's pretty awesome. I was in the camp that loved the original, and this is equally enjoyable. I do wish it had a co-op campaign, but the Survival stuff is damn fun. As mentioned before, I also encountered some slowdown and nasty hitches at a particular part, and there is a loading bug where parts of the environment are blacked out. Also, the daggers are this game's shotgun. You can zone like a fool with them and they come out quick with little cool-down.
Definitely recommended to fans of the original and anyone looking for a quality beat 'em up.