There are really only two types of corporation in existence: the one who considers opening the gates of Hell and the subsequent slaughter of hundreds of employees at the hands of twisted demons a reason to file for bankruptcy; and those that find some new, non-dismembered investors and jump right back in with nothing but optimism and a revised safety manual. The United Aerospace Corporation, believe it or not, fit into this latter category.

There are also only two types of potential UAC employees in existence: those who consider a mysterious 'accident' on Mars and subsequent empty cubicles by the dozen a reason NOT to accept a posting for a new mission to the red planet; and those who actually volunteer to take the job. One guess which category your character fits into'

So it is in this expansion pack to the critically acclaimed Doom 3, grimly subtitled Resurrection of Evil. Not content to write off their losses on Mars, the UAC decides to send a new crew of cretins out to ascertain the source of a mysterious signal. Here's a hint: mysterious signals from planets possessing portals to Hell are probably *not* worth investigating. But hey, if you've got the money and the morons, why not go for it? Enter your nameless marine character, who is A) not The Rock B) not Karl Urban and C) not paid anywhere near enough for this gig.

It's also all his fault- here's another hint: don't pick up the supernaturally pulsating organ inside a sealed vault on the planet possessing portals to Hell. But he does it anyway, and- wait for it- all hell breaks loose. Then it's up to you to guide your hapless hero out of the mess he made, slaying dozens of hell's denizens en route, and getting scared witless in the doing.

At its core, Resurrection of Evil is very much just an extension of Doom 3's core gameplay. There are still lots of dark corridors, scary surprises, intense battles and limited exploration. In fact the biggest change comes courtesy of two new weapons: the Artifact and the Grabber. Even though the whole game could've been avoided if you didn't pick up the Artifact, you might as well get some use out of it since you did. You'll use this unsettling organ to grant you access to a small selection of Hell's arsenal- temporary invulnerability, berserker strength or the originally named 'Hell Time''substitute 'bullet' for 'Hell' and you get the picture.

The other new weapon shamelessly 'borrows' the gravity-gun idea from Half Life 2, makes it less powerful, and gives it to you in the form of the Ionized Plasma Levitator, AKA 'The Grabber.' It's actually a pretty useful tool for taking down Forgotten Ones (the new version of Lost Souls), and throwing fireballs right back in the face of the imps who dare to launch them. It can also be used to toss around explosive barrels in a bind, which can be handy against clusters of weaker enemies, but aside from a few boss-battles, the Grabber is best reserved for less powerful foes.

There's also a double-barrel shotgun which should warm the hearts of old-school fans. This weapon is absolutely devastating and can shred even the toughest enemies to ribbons if you can get some shots in between long reloads. The trusty pistol has also gotten a bit of an upgrade- it now has a torch mounted under the barrel. Truly a useful tool for jarhead marines who can only focus on one task at a time!

Just like a good horror movie, Doom 3's strength lies in knowing what to expect'you know that if you pick up that enticing suit of armour it'll trigger some sort of trap, just like you know that demonic voices or blood-red lighting is a precursor to an attack. There's comfort in knowing what's coming, and the thing is, it still scares the bejesus out of you, and when the designers play on your smugness and reward you with a clattering pipe or other environmental effect, you feel silly but you still know something wicked this way comes.

Resurrection of Evil is no different, for better or worse, and if you've played the original you know exactly what you've got to look forward to. There's nothing radically different gameplay-wise, except maybe a little less reliance of PDA's and fleshed-out backstory to enhance the creepiness. There are a few new mini-games that you encounter through your journey- a Doom inspired version of Breakout, a weird game where you have to shoot a bear suspended in the air by balloons and a shooter involving Martian Buddy. Fans of the original will probably be happy that the formula hasn't changed, and this expansion pack is a brilliant extension to the story, but if you didn't dig Doom 3 there's nothing here that'll change your mind.

The visuals were Doom 3's real highlight, and Resurrection of Evil doesn't disappoint. It still looks fantastic (and truly awesome in 480p high definition for those so equipped), and the creepy lighting will still scare the crap out of you. A few of the enemies have been redesigned and there are some all-new bosses, and overall they all look frighteningly realistic. Slowdowns when battling 3+ enemies remind you it's just a game though, and it can get a little nasty at times, but on the whole the Xbox holds up admirably. And while there's nothing quite as expansive as Far Cry: Instincts, there's a few outdoor and open-plan levels which go a long way to breaking up the corridor claustrophobia.

It's all about phobia in the audio department though; like its predecessor, Resurrection of Evil has some of the most unsettling ambient sound on the Xbox. The background noises on the menus are bad enough, but in the game it plays on your nerves and really heightens the terror. Weapon effects are satisfyingly meaty, and there's nothing quite as satisfying as the epic boom of your double-barrel shotty to finish off the Imp whose screech just caused you to soil your pants.

Resurrection of Evil contains 12 new missions in the singleplayer campaign, which will probably take your average player ten hours or less to beat. It's a decent length given it's just an expansion, and the truly hardcore can always replay on Nightmare difficulty for a fiendishly hard challenge. In an unusual move, the expansion pack doesn't have the 2-player co-operative mode to play through the campaign with a mate, which is a major oversight.

And sadly, very little has changed on the multiplayer front from the barebones offering Doom 3 dished up. But what was merely 'undercooked' then now tastes positively rancid'there's new levels, but the new weapons don't put in an appearance, and it's still just boring. The tournament mode, in which 2 players fight while 2 watch on and then one of whom gets to play the winner of the match is possibly the dullest multiplayer mode ever, unless someone invented a 32-player, turn-based lawn bowls simulation.

To make up for it the developers have included a veritable treasure trove of Doom goodness- available from the minute you pop the disc in your drive is Ultimate Doom, Doom 2 and Doom 2: Master Levels. Oddly, you can play splitscreen co-op just fine in these games, which is a fun, old-school solution to the problem of the missing mode in the main game. Controlling your marine with the analogue sticks is a bit weird at first if you're old enough to have played the original games on PC, but you'll adapt pretty quickly. The games themselves are well emulated and play just right, and are probably worth the price of admission if you're a big fan of the classic games that started it all.