It takes a certain amount of technique to kill the baddies of Dead Space the video game, the Necromorphs. Shoot 'em in the head, and that'll only piss them off. According to this "Strategic Dismemberment" video from Dead Space special ops, it's a matter of timing and using your surroundings, especially if you run out of ammo and have to kill the alien with it's own ripped-off limbs. Click through and listen to Glen Schofield, the Executive Producer of Dead Space, explain the how-tos of alien slaying.
Dead Space is set in the future. The hero must explore a "planetcracker" mining ship known as the Ishimura, which has lost contact with the rest of society. Of course these miners have unknowingly stumbled upon an ancient alien race that wants to kill everything in sight, and it's up to the user to fight back. [Game Arena]