Just when some of us were starting to doubt them, it seems that Valve have done it again. I will confess that I, a devout Half-Life fan, was sceptical of the episodic direction in which they were taking the series. For me, Half-Life 2: Episode One just didn't hit the nail home. It was fine, but simply more of the same old story, pacing and action that the series is known for - as is the nature of episodic content I told myself. Then Episode Two came along, featuring as an integral part of Valve's unparalleled Orange Box.

I unenthusiastically booted it up for the first time, preparing for the same-old same-old content I was expecting. I hadn't paid much attention to it during development and it wasn't helped by its sister titles in The Orange Box somewhat stealing its thunder. It all starts in a predictable manner, and one that could be described as homage to the original Half-Life, as Gordon Freeman regains consciousness in a crashed train carriage. Following on immediately from the events of Episode One, you'll soon find yourself in a tutorial style introduction as you find your first person shooter feet and reunite with your old friend Mr Gravity Gun.

Just as you start to get comfortable, something dramatic happens - a peak in the story that sets the tone for a good chunk of the episode to come. No spoilers here though, as the story plays a bigger role than ever, the telling of which is of a particularly high standard - even for a Half-Life title, which already sets the bar very high. The trademark in-game cut scenes are here as per usual and you're likely to find yourself watching on with awe at the characters interacting as they bicker, joke and make some interesting revelations. The voice acting is of the usual terrifically high standard, and is so far in advance of the crowd that it's almost worrying.

The Source engine itself never ceases to amaze and has never looked so great - despite its age. It seems that due to feedback on previous instalments, Valve have decided to focus on providing more variety in the game's locations. One of the more memorable ones has you in a large mountainous area, which houses a prominent rebel base that you are tasked with defending from a swarm of oncoming Striders - just an average day for our Gordon Freeman then. Armed with a car, custom made anti-vehicle mines and your trusty gravity gun, the battle commences. As you dart between log cabins and pine trees, with the footsteps of Striders echoing in the distance, explosions reverberate from the mountainside. Planks of wood fly into the air in the near distance, as a Strider rips through a logging camp with its energy beam. If first person shooters are always to revolve around set pieces, then we can only hope they are all this good.

This episode brings two new adversaries to the mix; a new form of Antlion is present early on in the campaign, boasting a ranged poison attack that does some pretty hefty damage, while the Combine 'Hunters' certainly live up to their name. The first time you meet one in combat is a memorable experience, as the ever-wonderful blood pumping techno score kicks in to highlight the occasion. The Hunter's main attack sends a barrage of high energy flechettes in a forward arch, which stick to walls (or you) and explode shortly after. Get too close and they'll charge you, knocking you back and inflicting heavy damage. These guys complement their Combine brethren well and succeed in adding something fresh to combat situations.

In keeping with Valve's ethos of theme-based episodes, this outing has a constant feeling of travel. You are always going somewhere, to see someone or do something. Despite this it rarely feels linear, switching between claustrophobic tunnel-runs akin to its predecessors, and the newer, more expansive sequences. When you aren't running and gunning, you find yourself partaking in some interesting and usually very rewarding physics-based puzzles, which are as numerous and inventive as ever. All these elements are expertly intertwined and well paced, creating a very complete single player experience. Playing through the various chapters, even on the default setting, Episode Two stretches out to a good length - equalling that of other full priced alternatives in the genre.

Looking back at Half-Life 2: Episode Two, all I can think of is one fantastic gaming moment after another. It's strange to think that such subtle changes and additions can make the whole experience so much more enjoyable, but they have. The developer commentary serves the purpose of exposing some of the reasoning behind these changes and listening to it you can't help but sit back in admiration, not just because of their loyalty to the Half-Life series, but because of their absolute love of the craft. By staying true to the already exceptional foundation of the series and adding meaningful changes that enhance the player's experience even further, Valve have demonstrated yet again that in this ever-competitive genre they still have the ability to impress and excel.

Reviewed by Martin Oddy for AceGamez (All Rights Reserved).