Critical Consensus: Portal 2

RPS's Walker also finds some of the game's finest moments in the delicate, and sometimes throwaway, animation. "The detail kept taking my breath away," he writes. "I stopped to watch through one window, crouching to see past a rail, and saw the most extraordinarily elaborate, Pixar-like detailed sequence of about eight robot arms meticulously building a turret from scratch. It must have taken someone days to put this animation together."

Of course, the mechanics of the game's real core - the puzzles - come under the closest scrutiny. Welsh points out that, with the basic trick of the "use [of] the two mouse buttons or triggers to 'fire' two doors onto certain surfaces, allowing you to teleport yourself and objects, or subvert the laws of physics and three-dimensional space to reach your goal," so perfected in the first game, new tricks are necessary.

They're successfully introduced, too. "Splattering gel-like paint through cunningly-placed portals, or using portals to turn the faith plates into trampolines or orbital slingshots is a thrill that's both cerebral and visceral," says Welsh.

That those new devices and the obstacles they help surmount are central to Portal 2's appeal is in no doubt, says IGN. "Though there's a much bigger emphasis on story and character development in Portal 2, you'll spend a lot of time tangling with spatial reasoning puzzles in test chambers."

"Arriving at a solution will require quick reactions just as often as clear thinking, as portals sometimes need to be repositioned while soaring through the air or before timers run out," continues IGN's review. "This isn't a first person-shooter in the traditional sense, but at times it can feel like one as you zoom in with your portal gun to spy distant targets and frantically adjust your aim and fire with precision."

That genre bleed does not exclude the less agile among us, says GameInformer. "Portal 2 has fewer agility-driven obstacles, so less dexterous gamers shouldn't find themselves stuck on anything for lack of stick-flicking ability." Besseiner continues on to espouse the puzzles' "unbelievable creativity" and "wonderful" nature, bringing special attention to the co-op mode's particular charms.

That section of the game is not without it's own problems, though, says Giant Bomb's Ryan Davis, pointing out that: "having sets of portals with which to solve the puzzles, while also being fundamentally dependent on another player's puzzle-solving abilities, can unsurprisingly complicate things.

"This mode features a 'ping' tool which allows you to better direct your partner, though I found voice communication to still be an absolute necessity. Frustration looms throughout Portal 2, though if you're not operating at the same speed as your partner, you don't know your partner well enough, or, God forbid, you know your partner too well, it seems more likely to rear its head during the co-op campaign."

Welsh calls the co-op the "most natural and intellectually terrifying extension of Portal's puzzle-platforming lexicon" finding that it results in "one of the most satisfying and genuinely collaborative gaming experiences you can have with a friend."

So, despite a few minor blemishes, Portal 2 appears to have wowed critics into almost blanket appreciation. But will such critical acclaim necessarily translate into commercial success or will Valve's refreshingly highbrow approach alienate too many to put the game on the top sellers list? Time will tell. Until then, it's simply a matter of sitting back to enjoy one of the industry's greatest triumphs.