The game is set amidst the sprawling network of the Aperture Science Laboratories, a research corporation running experiments on the Handheld Portal Device or ‘portal gun’. This gun forms the backbone of what makes the game so special; it is a very clever concept. The portal gun allows you to make a gateway, or portal, between two points.

Whatever passes through one portal will come out of the other, while retaining the same momentum, which introduces some unique puzzles. GLaDOS, an AI computer, acts as a narrator and guide of some sort, taking you through a number of challenges that make clever use of this portal gun, from directing deadly energy pellets to traversing bottomless particle fields and moving platforms.

Such variety and uniqueness running throughout the game ensures that the experience never gets old, and is one that you’ll want to revisit time and time again.

What has impressed both critic and consumer alike is undoubtedly the gameplay. Portal is a joy to play; it really has to be seen to be believed.

What gets you through the game is not GLaDOS’s constant promises of delicious cake as reward for completing certain tasks, but it’s compelling, addictive nature. The portal gun really is a jewel itself, offering an innovative take on puzzle-solving that will engage even the most logical thinker on multiple levels. There are different ways you can complete increasingly difficult tasks; forcing you to make clever use of the lovable Weighted Companion Cube while at the same time having to navigate past gun turrets and toxic liquid to reach your goal. Portal offers thoughtful gameplay at its very best.

Part of Portal’s appeal is greatly illustrated by the dark, witty humor that ensues throughout. The game has none of the serious mask of most contemporary titles, and that is part of the secret of why it has achieved such mass popularity. Even the closing credits offer a source of amusement. Everything, absolutely everything, is geared towards making Portal enjoyable, engaging and most importantly of all, fun.

A sad point to note is that the game itself is undeniably short. You can complete it in a matter of hours and yet still feel like your skills were not stretched to their limit, that it wasn’t much of a challenge, and that you didn’t actually achieve anything. It is crystal clear that Portal is a brilliant game, but the longevity factor will definitely leave you with a sour taste in your mouth. Forming part of The Orange Box this compromise on length feels justified, but were you to buy Portal separately, you’ll be left wanting a bit more bang for your buck.

That said, it is hard not to keep coming back to Portal. While certain challenges and more difficult versions of six levels are unlocked upon the game’s completion, it merely offers an excuse to plunge back into the world of Aperture Science. To hear GLaDOS’s increasingly hilarious commentary, or simply to mess around with the portal gun (clearly one of the best weapons featured in a game since the ‘gravity gun’ of Half Life 2), Portal has replayability purely on the grounds that it is a great game.

If only there were more games like Portal. If only the gaming industry cared less about creating the most graphically realistic experience possible, and more about making games that are just plain fun. A simple concept, executed brilliantly. Portal truly is Valve’s finest hour.