Our fifth comparison, as we move onto the extra-terrestrial cast members while avoiding the overwhelmingly obvious influence of Aliens, is The Thing - in both visuals and behaviour. Dead Space’s Necromorphs are so unpredictable in their biology - so tentacle packed, so scuttly and so adept at crawling over ceilings - it’s impossible to work out where their weak spots are. Combat works through a system that EA call ‘strategic dismemberment’, but we call ‘lopping bits off them with laser wedges until they stop clawing at your face’.

Being an engineer your tools are like laser-enhanced versions of the cheese wires and bacon cutters you’ll find behind a deli counter - and as an array of teeth and bile scuttles toward you it’s up to you to take aim with three Predator-style lights and chop off legs, heads, toes and other bits until all that’s left is a pile of limbs and a cloud of arterial spray. A certain bloody nightmare creature may be best dealt with through a slice at the knees for example, though exactly which knees you’ll have to surmise through trial, error and an element of terrified blind fire. Break a foe in two and the chances are both parts will claw their way across the floor to you; consider an enemy decapitated, don’t be surprised if a head grows legs and jumps onto a table. Frankly, it’s terrifying.

Obviously then, there’s an element of Soldier of Fortune in the dismemberment stakes - you can take apart dead humans if you so wish as well - but the end result feels a lot more like the Resident Evil blueprint combined with the motions of firing circular saws at zombies in Half-Life 2’s Ravenholm. The Freeman cribbing doesn’t end there though - among Isaac’s engineering paraphernalia is a gravity toy we’re more than accustomed to, while the environmental puzzles in which it’s used certainly aren’t a million miles away from Valve-central. One tool that’s entirely fresh however, is the ability to place individual enemies (and indeed bits of furniture and thrown severed heads) into a personal slow-motion field - giving you time to choose the most pertinent slicing shot given your steadily falling ammo supplies.

Doom 3 probably wins through in the comparison stakes though, and before you start, it’s the stuff that id got right (or stole from System Shock 2) that’s been aped. For a start there’s that feeling of dank solitude and organic invasion that, away from the combat, Doom 3 nailed. Then there’s the audio logs left by the recently deceased and mutated - although this time slightly bereft of ammo locker codes.