Deus Ex: Human Revolution delivers the goods for fans of the long-dormant franchise.
They give you tons of worldbuilding and backstory, and took care to pay attention to every little details so that no matter where you look or what thread you follow, you'll never feel like you've hit the dreaded "Wall of Unreality" reminding you that this is all just a pretty (but shallow) facade built over a virtual world. Rather, you remain engrossed from start to finish, so much so that pressing the start button can be a jarring experience, and a reminder that you're not really Adam Jensen after all.
Choice is what stands out in Human Revolution. You can play the game as a brute gunning down hordes of nameless henchmen or as an nigh-invisible saboteur sneaking about in silence. Your decisions really matter, which is not something that can be said of most games, including many that make the same claims. Interestingly enough, while Deus Ex gives you the standard Good/Bad/Indifferent conversational options, unlike other games, Human Revolution does not reward or punish you for those choices. Fans of Mass Effect might appreciate that at no point in DE: HR will you find the response you REALLY want greyed out because you haven't been kind or rude enough. There are no anti-climactic moments like that to be found here.
The only place the game really lacks is in its story. The atmosphere is tremendous, the world plausible and believable, and plenty of the side missions have interesting threads, but the overarching narrative in Deus Ex is fairly generic and unspectacular. Major plot points seem to fall short of their dramatic mark, and some of the interactions are hard to believe. For example, a heated exchange Jensen and his boss, David Serif, reveals that Serif hired a private detective to do a background check on Jensen around the time of his hiring. Given the little intimated about Jensen's past, and the position he's been hired to (head of security for a giant biotech corp) is a full background check really something that would inspire feelings of betrayal? Is it something the boss would go to the trouble of hiding--especially since the means by which he hid it left the company open to a security breach?
The juicy bits lie in what was actually uncovered by the investigator, but because Jensen's is neither fleshed out or of any apparent relevance to the story going forward, the revelations within don't really have the impact they should.
Facial animations are also a drawback, with almost everyone in the world walking around with the stiff, expressionless masks of Botox junkies. But most games suffer from this shortcoming, particularly those making an attempt at photorealism. At any rate, it isn't enough to diminish the experience.
Deus Ex: Human Revolution needed to be a hit for the franchise to be something more than a cult classic last seen in the early part of the last decade, and on that front, it delivered. A few hiccups here and there keep this from being a GOTY candidate, but it's certainly worth an honorable mention, and should be enough to keep fans of the series excited for what's to come next.