As short as expected, though great to the last bit. Half-Life 2: Episode One shouldn't be missed, specially by the fans.
After the convoluted release of it's parent title, Half-Life 2, it's good to see this latest installment coming out smoothly and with the adequate fanfare. Episode One, as the name implies, is the first in a series of episodic releases that follow Gordon Freeman's exploits after the dramatic, and inconclusive, ending of Half-Life 2. This format, that takes part of a phenomenon that has been growing as of late, has it's strengths but also quite a few weaknesses. The obvious ones (in both categories respectively) are, of course, the smaller waiting times for sequels and, opposing it, the shorter length of the whole experience. Episode One lives and breathes these characteristics, and as long as you set your expectations accordingly, you're in for one hell of a ride.
The game starts right after the ending of Half-Life 2. Not soon after that, you're back in the action, fighting the Combine in a struggle to flee City 17 before it's unavoidable demise takes you with it. The first thing that you'll immediately notice is the fact that you're not alone this time. Alyx Vance, whom you meet in Half-Life 2, is with you and plays and essential part in keeping you alive throughout the game. This "duo dynamic" brings a breath of fresh air into the game without it losing it's roots. If anything, Episode One is closer to the original Half-Life than even Half-Life 2. Back, in full force, are the puzzle/platforming aspect of the series, which serve the purposes of making the game stretch a bit longer, help it be more varied, and mostly to strike the old-time fans with and unquestionable sense of nostalgia.
Also, the Gravity Gun sets in definitively as the worthy successor of the crowbar when it comes to the title of Freeman's iconic weapon of choice. The crowbar is noticeable absent from most of the first part of the game, and the dimension of that simple weapon's impact in this franchise hits you in full strength as you find yourself wondering what could have possibly happened to you little "friend". In regards to the Gravity Gun, it's worth mentioning that it plays and even more important part this time around, as you will be using it a lot throughout the game.
Gameplay-wise, you'll find that everything remains mostly unchanged which, in the end, is good. Fans of the series will feel right at home and, even though you have Alyx now to help you, things aren't all that different. Alyx is a worthy ally, and a great help, as she proves to be quite proficient in dispatching a multitude of foes without getting too much in your way. She's so good, in fact, that the game's difficulty suffers a bit with it. Half-Life 2 wasn't a particularly hard game (except, perhaps, for the infamous stand-off with the Combine soldiers in Nova Prospekt) but Episode One proves to be even easier. Alyx's seemingly infinite ammo supply and her impressive resilience (she's notoriously hard to kill, but it can happen) tones down the difficulty greatly.
When it comes to the graphics, the Source Engine proves to be aging rather well. The game looks great, and the character's expressiveness (specially Alyx's) is still very impressive. The small additions to the engine help it greatly to keep up with the natural technological evolution.
The sound is worth a special mention. Even though the game's soundtrack isn't as sharp as it could be, proving to be somewhat too intrusive at times, the voice work is perfect. All of the original cast is all back for another round and they perform as good as ever.
The game suffers, though, in it's replay value. Even though the story does progress a little bit, and even though the ending isn't as "painful" as the one before it, once you've seen it, you've seen it. Not much can be added with the needed care and attention, given the game's short length. This is probably the single greatest flaw of this sort of content, but, it's the nature of the beast. As such, Episode One does a great job circumventing those limitations. The experience is rich and worthwhile, and while not completely new, it's exactly what you'd expect from an Half-Life title.
In short, Episode One is a game easily recommended for a few hours of fun and excitement, though playing (in the very least) Half-Life 2 is required to make full sense of the story's development. It's mostly a release tailored for the fans that have been following the series, and in that regard it fulfills such task adequately.
If you're a fan, you shouldn't miss it. If you aren't, maybe it's time you become one.