There's almost definitely a similar post somewhere but I can't be arsed to find it and I wanna start a new one anyways.
Count on there being ***Spoilers***
So having literally just completed Dead Space 3 (on the second hardest standard difficulty) I must say, I'm almost tempted to say its that best of the three, with the second being good but the weaker of the three. In terms of story line and character progression it certainly blows the original Dead Space not only out of the water but out of the atmosphere. Its also much more engaging than Dead Space 2. At the end you've develop a real connection to the three main Issac, Ellie and John although I didn't play though in Co-op so I never really saw a great deal of John Carver. I'm just speculating that you give a shit about John from reviews.
Then the story line gives an overwhelming feeling of fighting for something much bigger than the characters. You get a great feeling of the importance and the scale of the task your trying to achieve. Although at the beginning these traits are not as strong. When your in space floating above the planet it can feel like your a little aimless but towards the end when your running though the alien 'machine' there is a very tangible sense of intense urgency. Your on the edge of your seat at the end. Or at least I was.
The atmosphere is also great, perhaps not as good as Dead Space 1 but there kinda intrinsically different. Dead Space 1 was more scary, every neco had the capacity to make you jump and that is actually still in Dead Space 3 but a little more watered down I s'pose. But Dead Space 3 has a larger scale, there's simply more necos to kill so each individual one isn't as much of a threat. But your certainly apprehensive of the inevitable attack of the mutated undead throughout. The human to human conflict is a bit 'meh' but makes sense within the story.
There is certainly enough variation of enemies to keep you occupied through the campaign. When you think you've seen them all they bring either a whole new contender or bring another old friend back into the fray. You keep getting new classes of enemies right to the end. One thing I would say is that this game did get on my tits a few times, when wave upon wave of enemies kept coming it can get a little tiresome. I did find myself getting rather aggravated multiple times during my play-through, more than once shouting at my screen in exasperation. Like getting through an entire wave to get killed by the last guy and have to do the whole thing all over again. It does a little Dragon Age 2 on your ass a couple of times but nothing too horrific.
But of course there are other gripes. Mainly the fact, from a technical perspective, that enemies disappear after you kill a couple more. This wouldn't be a problem if it weren't for the fact that they take their resources with them... You get resources from killed enemies by hitting them again after their dead but you don't want to waste good ammo on the already dead and don't have time to stamp them before another living contestant starts eating your face off. So that's a bit of a kick in the teeth. I played this on the 360 so maybe this isn't the case on PC. It especially annoying since i don't remember this being a problems on either of the previous titles. Anyway there's so much resources anyway, losing out on a few drops will most probably make no difference.
I know I haven't covered everything I could talk about but for one can't be bothered and secondly I can't really remember everything as of now. But anyway all in all I think Dead Space 3 is an incredibly solid game. It's certainly not for the light hearted and although may be a little easier than you might want it certainly doesn't come across as being easy as your getting hammered by multiple different enemies of different classes. I'll be putting this game and the series in a special part of my brain reserved for the very best. It's not perfect but what is and it takes a little time to pick up and even longer to get really immersive but if you can stick with it, all the way to the end, I'd wager you'll at least say a couple of good things about it. It certainly is something of a strenuous journey if played on harder difficulties.
I also imagine that if you could get ahold of a reliable someone who would be willing to devote something like 12 to 20 hours of their life to a game the co-op could be really good, letting you get to know carver looks to be interesting. But course I don't know that.