Price: £34.99-£49.99
Format: PS3, Xbox 360 (tested), PC, Mac
Developer: Valve
Publisher: EA

Refined, polished, focussed, perfected, Portal 2 is gaming at its most engaging; introspective yet social, poignant but simultaneously hilarious and, most importantly, an absolute joy to behold and explore.

Valve through-and-through, Portal 2 is a work of precision engineering, from the automated, on-rails, intro; through to the amazing scripting and voice work (the characterisation work by Stephen Merchant, JK Simmons and Ellen McLain is nothing short of brilliant); and finally on to that perfect design, which challenges players to rethink prior strategies, adapt to new rules and – shock of shocks – think for themselves.

Before I run out of superlatives to use, introductions are overdue. Portal 2 is a full blown sequel to the tech demo of sorts that was Portal – part of the collection of goodness that was The Orange Box and now also available via Steam. It was an original, enjoyable first-person puzzler, which saw a portal gun equipped runner solve multiple physics-based conundrums using portals and momentum. Portal 2 is a heavily expanded continuation along those same lines.

Back into the fray comes GLaDOS, a kind of female take on 2001: A Space Odyssey’s HAL 9000, not to mention Chell, survivor of Portal who wakes to find herself back in the human testing laboratories, though this time with an ally in the shape of the Stephen Merchant-voiced Wheatley, a more asinine take on the GLaDOS AI, and purveyor of some genuinely comical lines that will have you cracking up throughout. In fact, during the Wheatley-free sections I found myself genuinely missing him.

Whether you’ve played the original or not, it’s no real spoiler to say that GLaDOS was in bad shape the last we saw her. Designed to put humans through mind-bending tests, for seemingly no reason other than that was her programming, GLaDOS had taken on a god-like (OK, devil-like) persona; treating Chell like a rat in a laboratory maze. By eventually breaking free Chell took out GLaDOS once and for all – well at least until the bumbling Wheatley steps in during Portal 2’s opening salvo.

The tests themselves are a mind-bending assortment of physics-based puzzles, with portals, conveyor beams, turrets, light shields and momentum altering gels thrown in. Indeed to complete some of the tests which use combinations of these is not only cause to genuinely have to think, but also to have a euphoric eureka moment upon its completion, thus spurring you on to the next.

You’ll grow to love the short lift journey between tests where GLaDOS, Wheatley and co will speak to you, unveiling a little more of a storyline that will see you investigating the very origins of the Aperture testing complex. That Chell herself remains taciturn throughout – maybe she’s a relation of Gordon Freeman? – serves only to sharpen the words of the characters who do have speaking roles.

I could go on and on about moments of joy where the right combination of portal placement and gymnastics combined to catapult Chell to an exit but to do so would be to spoil the surprise; it’s far better to approach each test area with a unbiased perspective. Where that is trickier however is during the games multiplayer, which continues precisely where the solo-campaign leaves off.

In a way, it’s almost fair to say that Portal 2’s brilliant single player section serves as something as a tutorial to the two player mode. A distinct campaign in its own right, complete with story, the introduction of a second player – and important a second portal gun – changes the very fundamentals of the enterprise. Suddenly, huge juggling acts with multiple portals becomes a possibility, but only with cooperation and timing. The latter is supplied by the in-game timer, the former largely depends on who you’re playing with.

Grab a mate locally and Portal 2 becomes a hub for hours of debate punctuated by whoops of exhilaration as a well planned scheme pays off. Head online on the other hand, and prepare to face a wait to find a cohort taking the game seriously – the only way you’ll get anywhere. Yes, indicator portals and the timer do make non-communicative success just about possible, but half the fun’s in the debate and brainstorming so it’s worth waiting for the right Portal-buddy to come along – especially when the planning is this much fun.

A marvel of a release and, once again, justification of Valve’s “we’ll release it when it’s done” attitude to games development. Quite how the hordes of Call of Duty and Halo: Reach players will react to a FPS without bullets will be interesting to behold but give Portal 2 a chance, I guarantee you won’t be disappointed – game of the year? It’s early days but this is going to take some serious shifting.