When it comes to Deus Ex, I'm a contrarian: I think the second game was far better than the first, which was an ugly, buggy, tedious mess. Having finished Deus Ex: Human Revolution, it's probably the best of the three, assuming you skip its bizarre racial stereotypes. That's not just because the mechanics are better--although they are--or that the engine no longer looks like a bad Dark Forces mod. What I find most praiseworthy about Human Revolution is the way it actually engages with science fiction on a level deeper than laser swords and nano-babble.
Fundamentally, this is a game about progress. The developers use transhumanism and human enhancement (not to mention stabbing people with your robot arm-swords) as proxies for the ways that innovation interacts with class, with government, and with culture. This is all pretty standard fare for sci-fi, but it's something few games set in a science fiction world bother to raise. You don't see Gears of War dwelling on the morality of war, or Portal (for all its genius) drawing explicit lines to our relationship with science. Whatever annoyances it might have, I really respect Human Revolution for grabbing a big concept and taking it seriously.
This thoughtfulness extends all through the art design, which is genuinely great--probably the best since Mirror's Edge, in the way that it's both striking and still very much a video game. The visual theme that Eidos Montreal reportedly wanted to emphasize was Rembrandt, which means there's a lot of grainy, gold light bathing the scenes, outlined in clean digital polygons for interactions. The character animation during dialog could be sharper, but the visual worldbuilding is very thorough, and there are a couple of setpieces (like the all-white room late in the game) that are quietly impressive.
The attention to visual detail extends to the costuming, which really carries the Renaissance theme. But this is also a game about people merging with machines, and so mixed in with the capes and the ruffled collars are garments made with a kind of "low-polygon model" structure of tesselated triangles--as if some future fashion designer will be inspired by Battle Area Toshinden. Which is not, honestly, at all implausible, and is a pleasant change from the usual dystopian leather fetish. Even the body armor worn by the soldiers evokes a combination of iron plate and corsetry. Also nice: Adam Jensen's obligatory black trenchcoat is topped by shiny black velvet shoulder panels in a floral pattern, which I think is what all the hip cyborg messiahs are wearing this season.
There's a long history of games that compete visually based on fidelity and/or horsepower, like every iD title ever. And then there are games that go for highly-stylized rendering methods, like Team Fortress 2 or Wind Waker. Human Revolution operates somewhere between the two: it's a mostly-realistic engine, even one that's a little bit behind the times, being used to render a realistic world with a strong editorial style. It has a fashion sense, so to speak, one that helps to pull together its theme and world. I think that's part of why it feels so much more cohesive than the generic cyberpunk of the previous two.
But does it ultimately succeed in making a statement? It's one thing to raise provocative questions, but another to actually pose an argument. I think the real shame is that Human Revolution gets held held back at the last moment by being a Deus Ex title, meaning that it privileges pointless choice over point of view. Late in the game--late enough that it's comically irrelevant to the plot--two characters make their pitches for and against regulation of human enhancement technology. Reach the very end (this is no spoiler) and you'll be given the option of picking one of those plans, or two other equally-unsubtle choices, all of which are literally just a button-press away from your final save point. It is, just as with the original games, entirely cosmetic and consequence-free.
The problem is not that the developers needed to pick a side, but that the final choice feels needlessly reductionist. It comes after hours of stories that examine the costs and benefits of progress from all angles: exploitation of workers, addiction, medical advances, relationships, and scientific ethics. Human Revolution does a surprisingly good job of presenting these with nuance and depth, and then asks you to pass judgement on the whole issue in the most biased way. In contrast, Bioshock set up its political and economic dilemmas, stewed them with a set of rich characters (goofy final boss aside), and then just left them there for you, an approach that's substantially less insulting than "Press 1 to exalt Ayn Rand's values of selfishness, press 2 to embrace socialist altruism..."
In the end, that's why I suspect that RPS's John Walker was right to say that this is smartly-made by smart people, but it's not a smart game. Mechanically, it's sound: I enjoyed playing it much more than I ever thought I'd like a Deus Ex game. It looks great. It presents a complex world filled with interesting situations. And then it undermines much of that credibility--not all, but a large majority--by reverting to Choose Your Own Adventure in the name of nostalgia. This, fellow gamers, is why we can't have nice things.