This game is just absolutely incredible. To begin, though, it's worth pointing out that this isn't a game for everyone: in particular, if you have no interest in narrative-focused games then don't bother playing Enslaved. The gameplay is enjoyable, sure; clambering around the gorgeous environments is fun, and the combat is solid (if a bit repetitive). The focus for Enslaved, however, is definitely, without a doubt, on the story it tells, the feelings it provokes, and the experience that it leaves with the player.
It would be easy to say that the game isn't breaking any new ground here, since it's an adaption of Journey to the West, but the writers took the building blocks of that familiar story, placed them in a completely different setting, and created something both fun and compelling. Aside from the very end, there are no surprises in the plot as everything is clearly foreshadowed; if anything, though, this just increased the impact of certain scenes, as the game builds up feelings of excitement, anticipation, or dread.
To me, this is the key to Enslaved's success: every aspect of the game is crafted almost perfectly to evoke these strong emotional responses, from the music to the writing to the visuals (especially the excellent mo-cap for facial expressions, which adds a whole lot to the delivery of each character's lines). By the time the game ended, it really, truly felt like a long journey, and to me that's the most satisfying emotion after completing a game--even with its disjointed environments and simple, text-based transitions (a la "two weeks later", etc), it still conveyed all the feelings one would expect with a subtitle like "Odyssey to the West."
While the gameplay isn't the focus for Enslaved, though, it's still very much enjoyable. The combat felt a bit simple, and there were a few too many fights that were a little bit too long, but fighting has a really satisfying, visceral feel to it. The boss battles perfectly encapsulate both the positives and the negatives of combat: they're exciting and well-crafted, but they take a bit too long to beat and a couple fights are recurring and get a bit boring. About two-thirds of the way through the game, I was starting to get sick of the regular encounters with enemies, but it obviously wasn't enough to dissuade me from the game entirely. The platforming, while a bit simplistic in nature, never got old to me; the puzzles are solid if not spectacular, and the collectibles are a nice diversion without taking away too much of the focus from the rest of the game (Alan Wake really suffered from this).
It bears repeating, however, that Enslaved is first and foremost a narrative-focused game. It's a fantastic choice for those who enjoy video games as a storytelling medium, as it provides an incredible experience to the player. It's not as fully realized as something like Spec Ops: The Line--where every single aspect of the game contributed to its narrative--but Enslaved does an excellent job of combining a great story and fun gameplay into a single package.
Also, if you played and enjoyed it on a console, it is absolutely worth picking up on PC; it looks and runs very well, and it deserves to be seen at 1080p+/60FPS.