Valve are such teases. I polished off Half-Life 2: Episode One last night (from start to finish) in a little over four and a half hours. I would have done it quicker, but the game had a sound glitch and literally killed my soundcard. Doesn't matter what I do with the drivers, I can't get sound out of it. Not even a squeak. Windows, of course, says it's working perfectly, and not even reinstalling it from scratch helps. So it's just as well that I invested in a pair of Sennheiser PC155s a couple of years ago (the ill-gotten gains from the Devil's Advocate I did for PCG, which - ironically - appeared opposite an advert for the very same product). They have a USB interface on them that acts like a soundcard, and I can't tell the difference between the sound quality from my Audigy LS and the PC155s, so... whatever. Saves me from forking out on a new soundcard, anyway.
At least it didn't ruin my enjoyment too much. HL2:E1 has a lot of nice moments. Quite a few annoying ones too, but that was mainly due to a lack of caution on my part, not noticing the Metrocop on a gun turret, or the mines hidden behind barrels, etc. Whilst short, it's certainly sweet, with plenty of changes of pace and lots of emotional weight, particularly from Alyx. There are a couple of really nice set pieces, too. The obligatory gunship and strider duels are pretty intense, with a couple of "You've gotta be kidding me!" moments.
If you liked Alyx in Half-Life 2, prepare to fall in love all over again. Now that you spend almost the entirety of the game with her, you really get more of an insight into her character. The reason I like her is because unlike most women in videogames, she's not just there as a love interest or as a token feminist. She's got real depth of character, and is an amazing woman. I'm not just talking about her physical attractiveness. Of course, that's a part of it, but whilst she's brave and psychologically tough, Alyx isn't immune to what's going on around her. She's emotionally vulnerable, too: she's affected and driven by the human cost of the tragedy caused by the Combine's occupation of Earth. When Alyx has a rather disturbing encounter with a Stalker quite early in the game, she just doesn't shrug it off instantly - it takes her a few moments to catch her breath and regain her composure. And that's what makes Alyx (and the game) so special. It recognises that game heroes aren't supermen. They're ordinary people plunged into extraordinary circumstances, where simple survival is an achievement. They have to do extraordinary things, because they don't have the choice anymore.
The only criticism I'd make of Episode 1 is of the ending. It pulls far too similar a trick to the ending of Half-Life 2, and seems a little mistimed. Given that you've played through the entire episode trying to escape from the city and the explosion of the citadel's core, ending the game without letting you know whether you've succeeded or not seems a little perverse. Of course, we know that we've survived the explosion, otherwise they'd be no Episode 2. So why not find a better place to end the narrative, at least giving the player the satisfaction of feeling that they've achieved something, such as reaching one of the Resistance's safe areas and meeting up again with Barney, Eli and Dr Kleiner?
I'm sure that the reasons behind it will become clear when we get our hands on Episode 2, but for the moment, I'm left a little unsatisfied, or unsated, rather than disappointed. I've replayed a little of it with the developer's commentary on, and it's pretty interesting stuff, especially the design tricks they use to draw the player's eye to cool stuff going on. I recommend you leave the commentary off until you've completed the episode once, however. It doesn't change the experience that much, but it does get in the way of Alyx's commentary, which is far more important, in terms of enjoying the game as a playing experience.