Regards,
The rest of the world.

If you've been paying any attention at all to video game sites lately, you'll notice that they've been handing out game of the year awards to one of two games. The first is Super Mario Galaxy, and it's not hard to imagine why. The game is really, truly brilliant in a way that no 3D Mario game has managed previously. Nintendo nailed this one, and for that, we are thankful.
The other game is Portal. Portal is probably the most significant game released this year, and also the one I had the most fun playing. This is why I'm nominating it as my personal game of the year.
Sure, you can argue that it's too short, or that it's just there to fill out space in Valve's Orange Box release. Neither of these things really get the point, though. Portal is brilliant in every way. From start to finish, the game is nothing short of brilliance.
The length issue is particularly bogus. Portal is exactly as long as it should be. A lot of people get tied up on game length, and think that if a game isn't 40 hours long, then it's too short. The reality is that different kinds of games need different lengths. It's fine for a high-concept Japanese RPG to run into the 40 hour mark, because of their scope. Most first-person games have been clocking in at around 10 hours or less.
But these are just a physical characteristic. What's more important is how well the game uses the time it gives you. At 6-7 hours in length, Bioshock felt far too short. The final third of the game suffered from poor pacing that made the ending seem rushed and incomplete. The game didn't use its length well. Half-Life 2, on the other hand, has a few sections that could probably be a bit shorter (Highway 17 and Nova Prospekt in particular feel a bit too drawn out).
Portal, though, comes in at maybe two hours in length, and that's just perfect. It doesn't need to be any longer, or shorter. At no point does it feel rushed or unfinished, and nor does it ever feel drawn out. It feels just right, from start to finish.
Perhaps the best way to look at it is like this: Portal is the only game, ever, that I have finished eight times. From start to end. Each time is just as much fun as the last. I often play through the whole thing just to show it to other people. Even my sister liked the game, and she hasn't played a video game seriously since Mario Kart 64.
This is all without even mentioning the other things that make Portal so brilliant. On the surface, the idea of a game where all you have is a gun that shoots portals and carries objects seems a little simplistic. It sounds like a fun idea for a few minutes before you start running into the limitations. It doesn't seem like an idea that can carry itself over even the short length of Portal.
Describing it that way fails to take into account how damn funny Portal is. The voice that talks to you (in fact, the only character in the game besides you) is GLaDOS, and she is essentially a vindictive child trapped in a supercomputer's body. By the end, you almost feel pity for her. She helps give Portal its unique atmosphere.
I think that Portal must, in the end, be given a nod as game of the year because it's so important. Valve have, with a two hour game that was originally a student project, changed the boundaries of what a first-person game can be. The whole playing field is different now. Dramatically so. Portal does, in two hours, what Bioshock couldn't do in seven.
It changed games.