The words 'Episode One' never really fill me with confidence. Since being burned by the Star Wars film of the same name, I am predisposed to treating the moniker with suspicion. Thankfully, the first follow-up to seminal shooter Half-Life 2 goes a long way to curing my cynicism.
The Half-Life franchise is the stuff of PC legend. The original was built on a heavily modified version of the Quake engine, and was arguably the first FPS to marry blasting action with a proper storyline. Featuring one of the best introductions to a game ever conceived, it dropped you into the shoes of a physics scientist, Dr Gordon Freeman (who actually looks just like Wil – ed.), who just happened to be in the wrong place in the wrong time - cue a research disaster and a mission to save the world.
The original Half-Life introduced the G-Man, a mysterious government agent who appeared to possess some pretty awesome power. He brings you out of a 'retirement' to start the sequel, released at the end of 2004, in order that you might save the world again. This time, humanity is in the grip of a sinister group called the Combine who have locked down major cities and rule with an iron fist. Combine guards patrol the streets and the 'Free man' - pun-tastically, that's you, by the way - is also a wanted man.
Half-Life 2 ended with Freeman apparently defeating the leader of the Combine, Breen, and destroying the Citadel at the centre of his power. Unfortunately, you also put your pistol-toting-pseudo-girlfriend, a lovely lady called Alyx, in mortal danger. The cliffhanger ending had the G-man appearing from nowhere to apparently whisk you away from impending doom, leaving poor Alyx to a fate unknown.
Half-Life 2: Episode One picks up straight from that point. The introductory sequence shows Alyx being saved by your one-time enemies and now-time friends, the Vortegons. She is reunited with you in the opening moments, but the bad news is that the Citadel is about to blow, big-time - and there's not enough time for you to get out of there. The answer is obviously to journey back into the city to prevent the mass-destruction of the Citadel, thereby saving yourselves.
And thus begins the roller-coaster ride that makes up Episode One. First-time players will crack this $20 expansion pack open in around four hours. But is it any good?
The first thing to realise is that Episode One is merely one part of a larger whole. Half-Life 2 entertained us with a varied mission structure and locale - from claustrophobic shooting in a bunker to jet-boating down a lake. The variety kept gamers entertained and always on their toes. In contrast, Episode One can feel more straightforward, with large chunks of the game spent in the same place with the same weapons and the same mission.