Every now and then a game comes along that requires serious attention, simply because it is pure genius. Usually such games are mind-boggingly simple, and feature an idea so obvious that it makes other developers slap themselves in the face in disbelief that they didn't think of it. Portal is the latest such game to follow in this tradition.
Portal follows the adventures of a young lady named Chell, who, for reasons never explained, has been held in stasis for an unspecificed amount of time at an Aperture Science Enrichment Facility, waiting to undergo testing and training on the Handheld Portal Device 04 (aka, 'the portal gun'). Chell doesn't encounter any other people, but is guided through the testing facility by GLaDOS (Genetic Lifeform and Disk Operating System), an extremely eccentric AI which becomes increasingly demented as the game proceeds, directing Chell into increasingly hazardous test chambers (including a 'live-fire course usually used to test military androids') but urging her to continue through the promise of cake.
Each test chamber consists of a puzzle which the player must overcome by use of the portal gun. The gun can create portals on certain wall surfaces. Two portals can be created. By simply stepping through one, you step out of the other. Puzzles can be very simple (crossing a chasm by firing a portal onto a wall on the far side and another next to you, and stepping through) or mind-crushingly complex. Since you retain your forward momentum when you pass through a portal, some puzzles involving crossing vast gaps (with non-portal-compatible walls on the far side) can be overcome by generating a portal at the bottom of the chasm, another one on the wall behind you, falling down the chasm at tremendous speed, which then gives you momentum when you pass through the portal to cross the vast gap. Dealing with sudden shifts in orientation and direction is key to progressing through the game.
The puzzles are complicated by the increasing addition of dangerous obstacles, such as energy spikes you have to direct through portals to generators to open up the next area of the test chamber but which will kill you if you touch them, and the sudden addition of robotic sentry guns to certain chambers (which comically tell you they hold no ill wishes when you inevitably destroy them). You also have some help in the shape of the 'weighted companion cube' or 'box' which you can use to press switches, bat aside energy spikes or deflect sentry gun bullets. For a non-sentient inanimate object, the companion cube soon becomes a trusted ally in the game and the puzzle which requires you to 'euthanise' one of them is strangely disturbing.
Of course, there's only so many times you can solve puzzles revolving around portals and the laws of ballistics before it becomes a bit old, and to their credit the developers realise this and only provide twenty test chambers. The completion of the last chamber triggers the second (much shorter) stage of the game where you have to use your carefully-gained portal skills to escape the facility once it becomes clear that something is not right in the world outside (this is where the link to the Half-Life universe is hinted at), leading to the fiendishly satisfying final confrontation and the best end games credits sequence ever.
Portal is a tremendoulsy simple idea, fantastically well-executed. I can imagine the Half-Life 2 team at Valve feeling a bit embarrassed about the fuss they made about the gravity gun when Portal shows off the capabilities of the Source Engine's physics engine with much greater finesse, elegance and originality. At about 2-3 hours in length, it doesn't outstay its welcome (and your brain will be aching by the time you get to the game's conclusion) but it does leave you wanting more. Where a possible Portal 2 could go is unclear, but the game hints that the Aperture Science facility has been abandoned due to something crazy happening in the world outside, and it isn't too hard to tie this in with the Combine occupation of Earth in the Half-Life 2 series of games. Whether this means that any sequel will see Chell taking on the Combine with the portal gun, or perhaps involve her meeting Gordon Freeman, is unclear, but it's an intriguing notion.
Portal (*****) is superb. It's original, it's funny, it's well-executed, it's perfectly-timed and has a sense of humour as black as midnight. It's part of The Orange Box for PC, PS3 and X-Box 360 (see the Half-Life 2: Episode 2 review for Amazon links) and is available now. Go get it!