The original Dead Space (PC) is available for only £3.75 at Steam
They also have Dead Space 2 for £17.99 but it's cheaper at £12.99 over at TheGameCollection ( http://www.thegamecollection.net/dead-space-2-pc-p-4140.html
Only the Dead Survive.
A massive deep-space mining ship goes dark after unearthing a strange artifact on a distant planet. Engineer Isaac Clarke embarks on the repair mission, only to uncover a nightmarish blood bath — the ship's crew horribly slaughtered and infected by alien scourge. Now Isaac is cut off, trapped, and engaged in a desperate fight for survival.
Strategically dismember the Necromorph enemies limb by bloody limb.
Zero gravity combat means terror can strike from anywhere.
Uncover the horrific truth of this shocking thriller.