I'm about halfway through the campaign now, and what a stupidly great and satisfying game this is. Not just comparing to other shooters, I can't think of anything in this view perspective I've enjoyed playing nearly as much since the first BG: DA.
In fact, to me this is such an obvious quality game that I cannot for the life of me see how it could have garnered some of the low review scores it has got from some places. They are not affecting my enjoyment with it of course, but someone not familiar with the game will see that it's not getting much better reviews than that atrocity Zombie Apocalypse, a game that's realistically an order of magnitude worse, and just skip on it. What they've made here is by far and away second best twin stick shooter on PSN, right after their own SSDHD.
Maybe they should have gone with some other theme after all, but there's really so few zombie games on PS3 that I can't see it bothering anyone, especially when the entry is this good.