Ive put about 7 hours into Dead Space 2 so far and I've loved every second of it.  Im glad they moved the game to a setting that allows a larger variety in level design.  The first game was really good but everything looked the same which is the reason I never beat it.  I never felt like I was going anywhere.  Like I said that isnt an issue in Dead Space 2.  There are plenty of areas to the game and all of them have their own unique look.  Some of the missions or chapters require you to traverse the same areas multiple times to complete multiple objectives but every time you go back through someplace there is something different whether its a change in lighting or bodies everywhere its at least slightly changed. 
 
One issue I have in the game is weapons.  I almost dont want to buy new ones because im not sure what works best and how much ammo ill find.  I stick with the starting cutter and I use the javelin gun along with the pulse rifle and not much else.  It hasnt caused an issue so far.  I dont know if its me not wanting to spend the money on anything but power nodes or if its a flaw in game design but it was exactly the same way in the first game.  I think they need to seperate the power nodes from the store or make it so you find guns instead of having to buy them.  Otherwise I dont see myself changing weapons up any time soon. 
 
Speaking of power nodes I found a glitch thats related to the rooms locked by nodes.  I dont know if this works on all these rooms but its happened twice so far and if abused it can greatly unbalance the game.  All you do is make a save, open the door with a node and then take all the stuff.  Make a second save after going in the room, quit and reload the second save.  The room should be full of stuff again.  In one room I managed to gather over 40,000 credits plus items in about 10 min of time.  All I would do is go in the room take all the stuff go out, save/quit and load up again and go back into the room. 
 
I decided to revert to the save before I went into the room the first time because I dont want to ruin my first play through.  I could easily do this glitch and completely upgrade all my gear and buy everything because right down the hall from the node room is a store and bench.  I probably will abuse the crap out of this little flaw on my second play through and maybe once ive got more power nodes than I know what to do with ill be able to convince myself to buy some new guns. 
 
EA has a good thing going with this series.  Its got the creep factor nailed.  No game before or since Silent Hill 2 ever gave me the creeps or made me scared to walk through a door but Dead Space succeeds in this regard brilliantly.  Not only does it have the graphical atmosphere down it has some incredible sound design to go along with it.  Hearing clanging metal and things being knocked around in the distance is always disturbing.  Just when you think you know what to expect or you think you have the pace of scares down they change it up.  Rooms you know for a fact are safe arent, and places you are convinced you will be violently ripped to pieces end up being calm and safe.  This kind of tension is what makes this genre so good and the execution here is damn near perfect.  Not only that but gunplay is spot on.  If this wasnt a horror game it would make a really good action shooter.  Its just very satisfying to play and its the kind of game you dont want to stop playing until you beat it and then chances are you're going to want to play again.