[Disgruntled Intern]

Dead Space is great. It's really challenging, and makes you take care what weapons you use when. The Upgrade node system is neat, too.
Basically, you can commit a node to either your weapons, RIG (your suit), the Stasis pack (a RIG mounted tool that slows things down), Or your...Kinesis. Which is basically an extremely simplified gravity gun.

These are then broken down into seperate categories on a 'circuit'. Sort of like a fuse, or wiring, each node allows you to connect another node to the adjacent one, but not every single node has a use.
O=Used node
+=Open node that can be charged
x=Open node that cannot be charged
- and I='Wiring', the lines connecting nodes.
(Ammo)
O------------O--------+
(Damage) I(space)I
O------------+--------X

So while you may be tempted to simply upgrade the first echelons of every item you come across, it pays to commit to the empty nodes in the long run. I can understand if you find this boring but to me it's AWESOME.

Also the guns and enemies are great.

What he said. Boss fights are pretty good, too.