More about the game play (taken from Wikipedia):
The player takes the role of Isaac Clarke (named after science fiction writers Isaac Asimov and Arthur C. Clarke[5]), an engineer who must fight his way through a stricken mining ship infested with Necromorphs, a hostile, virus-like, free-roaming alien DNA with the ability to reanimate the bodies of the dead, turning them into grotesque monstrosities. The game features an 'over the shoulder' third-person perspective,[3] similar to games Resident Evil 4, New Mexico and Gears of War. The interface does not feature a traditional head-up display. Instead, information is relayed to the player via holographic projections, which hover over Isaac's weapons and armor.[6] An in game store can be accessed where items can be bought and sold.
Isaac battles a Necromorph.
Zero gravity and decompressed environments also appear in Dead Space, and Isaac can navigate through them using his pressurized suit and magnetic boots. Some levels even lead out onto the surface of the ship's hull. Floating debris presents a hazard, however, and Isaac can lose his footing and simply float off into space.[6] Isaac's suit also has a limited amount of air while in airless environments, which can allow him to suffocate, forcing the player to move faster when in these situations. In keeping with Isaac's profession as an engineer rather than a soldier, weapons in the game are mostly improvised from mining tools, such as a plasma cutter, hydrazine torch used as a flamethrower, and a force cannon emitting powerful shock waves, although a triple-barreled automatic military rifle is also available. Stasis can be used in the game to slow down enemies and objects temporarily, and a kinesis module to pick up and throw items. Text, audio and video logs can be found throughout the game which detail the final moments of the crew, and sometimes provide a bit of information on the story.
Combat in Dead Space becomes complicated when Necromorphs do not simply "die" after receiving a certain number of gun rounds. In fact, depending on how they are wounded, Necromorphs can adopt new stances and tactics, even sprouting new limbs and giving birth in the process.[7] To defeat the Necromorphs, Isaac must use "strategic dismemberment," the methodical severance of specific limbs or sections of the Necromorphs.[8] Dead Space's executive producer, Glen Schofield, has said that "the primary theme of Dead Space is dismemberment,"[6] and early previews of the game noted the high levels of gore.
I'm not giving away the story but suffice to say it has been complimented by reviews across the board.