The bad news first: Human Revolution is more like Invisible War than the original Deus Ex. The "RPG elements" are essentially stripped away, for example with no branching paths of weapons skills, simply making you a Call Of Dudebro expert in any gun or grenade you happen to pick up. It has that weird cheap-looking portrait art and twitchy herky-jerky character model animation that Invisible War had. Though the length is nearly the same (about 30 hours here doing most of the sidequests, as compared to about 35 for the original Deus Ex), the complexity is greatly reduced; only in a few cases do decisions you make come back to have varying repercussions later, and you can't pre-empt boss battles in the variety of ways you could in the original. Human Revolution is actually less complex that Invisible War in that regard, because it dumps the "faction" approach entirely (in which each mission would have varying objectives that aligned with the goals of one of the game's power groups or another, and you chose the approach that you preferred), only giving you a real "moral choice" at the very end of the game, where you're literally put into a room with four buttons to choose from that each give you a different ending. There's no positional limb damage, for either you or the enemies; enemies are largely desensitized bullet sponges that will run right through multiple headshots not missing a beat and still firing away at you with perfect accuracy.
 The good news now: Human Revolution is markedly better than Invisible War. When the IP shifted from now-defunct Ion Storm to Eidos, there was an almost complete turnover in staff (including the loss of lead designer Warren Spector) from the previous two games. The new guys didn't get nearly everything about what made the original game so beloved, but they did manage to restore a few things that were lost in Invisible War; chiefly, interesting level design that rewards players for exploring every nook and cranny. A stealth approach to combat is also much more viable again, with an instant takedown, a highly effective short-range stun gun, and a pretty good long-range tranq rifle at your disposal (in fact, stealth is pretty much mandatory now as enemies will shoot your balls off when out in the open, even at the beginning). It also has a more compelling "cyberpunk" setting as well as more engaging characters and story.
 If you've never played any of these before, Deus Ex is in the "thinking man's FPS" mold; blending elements of conversation, hacking, stealth and puzzle-solving into the usual "kill everything that moves" shooter framework. The original Deus Ex wasn't the first of this type of game, but it's largely still regarded as the king of the hill, delivering the most satisfying (and replayable) overall experience. 

I think the best way to sum up the unique appeal of the first Deus Ex is in describing the way it handled the traditional "boss battle." There are really only three enemies in the game that could be considered "bosses", and where and when you face down two of them varies depending on how you approach the game. There are "kill phrases" you can find that actually destroy them instantly; one is found by exploring and hacking computers off the beaten path, the other potentially comes to you as a result of a choice you make early in the game. Even if you miss those, however, there are still numerous alternatives to a mano-a-mano slugfest with either. One can actually be murdered at an opportune moment in private, before you even get to the point of fighting them. I think the game might actually technically let you sneak/run past both of them, if the circumstances are right.
 Human Revolution, by contrast, takes the "big room you can't leave for no good reason" approach to boss battles. In fact, the bosses here are probably the biggest bone of contention in the game; so much so that the lead designer issued a formal apology for how bad they were. The issue being that they are the ultimate Tank Bullet Sponges; but there's always some cheap tactic that you have to abuse to beat them, since there's really no other alternative. While this aspect was disappointing, I didn't think it was solely the reason why this game seems inferior to clunky ol' Deus Ex, or even one of the bigger ones.
 More of a problem is that the new developers often seem to be aping elements of other "thinking man's FPS" - as well as the original Deus Ex - without necessarily fully understanding why they work in their original settings. One example is the "social battles"; a handful of conversations throughout the game where you are trying to extract information from someone by making the right choices in conversation. There's an optional augment that clues you in to what it is they want to hear; without it, however, it doesn't feel like there's any real reasoning behind the options you select, and you're kind of just guessing your way through. This is particularly egregious in an early confrontation at a police station, where the conversation references events from the character's past that the player has not yet been made privy to. 

It's not a game-breaker because it happens so infrequently, and you never "have" to win a conversation anyway; but I get the feeling this element was kind of clunked into place late in the development cycle after the devs played Alpha Protocol, thought its branching conversation system was neat, and wanted some kind of approximate even if it was rushed and nowhere near as complex or interesting. 

In terms of cinematic direction and overall look the game bites off the first Metal Gear Solid game pretty hard; we've already covered the boss problem, but the first boss is a really obvious clone of Vulcan Raven, just without even half the creativity or good design sense. And while the detail-laden and exploration friendly environments are definitely a welcome thing, by the end of the game prowling through enemy bases starts to feel like a highly repetitive chore. In Deus Ex it was fun because you felt you could shift the game experience so much by simply exploring and seeing what options were available to you, but Human Revolution quickly makes it clear that it's taking you through a linear and mostly scripted series of events, and your only real choices in any given area are in how you choose to subdue/kill the enemies and whether you hack through a door or simply punch in a nearby wall instead. 

The lack of RPG elements and specialization comes into play again here; in the original game it was vital to explore and forage widely, because you really needed the upgrades. Here you barely even need any augments because your character is so good with every weapon he stumbles across, you can get away with approaching the game like a Dudebro cover-based shooter for the most part. The game also tells you that you can't fully upgrade all your augments; turns out that's technically not true as people have already found ways to do it, but even without playing the game as Super EXP Scavenger you'll max out nearly everything by the end anyway ... and it's easy to choose the stuff to ignore because it's redundant and poorly thought-out. For example, all of the radar upgrades and the "see through walls" thing are essentially useless because the stock radar functions so well. Hacking, the super jump, more battery power and dermal armor were the only ones in the game I found to be anywhere near vital, and you could max all those about halfway through the game if you focused on them.
                                               He died knowing his fondest wish 
 The music needs to be mentioned as Alexander Brandon's score in the original game was a huge part of the appeal and atmosphere. In the first Deus Ex, when you reached China, you were greeted with this memorable tune that quite possibly may never leave your head. In Human Revolution, when you reach China ... there's barely any music at all. Nor is there at most other points in the game; it follows the trend of most AAA games these days of sacrificing strong melody for Hollywood-style "ambient" stuff that works OK as an atmospheric background, but is instantly forgettable.
                                                                            ok seriously 
 The game is often lauded for tackling "deeper issues", but my feeling was that it only does so in a very cursory way; it waffles back and forth between media control and transhumanism as its central moral themes, but never says anything original (or even really compelling) about either, and kind of rattles to a weak finish with a rather poor ending that smacks of "dev budget is running out, hurry up and get this shit out the door." The "media control" angle is dispensable because it relies on exceptionally unrealistic Metal Gear Solid 2 Supercomputer to function, and "transhumanism" might end up being a major issue IRL in 10 or 20 years, but right now it really isn't, and Human Revolution's take on the concept is kind of muddled anyway (kinda like Metal Gear Solid's perpetual "war is awful ... but GODDAMN WAR IS BADASS" stance.)
 Some of all this had to do with it being an entirely new team (and no Warren Spector) involvement. Some of it had to do with the business realities of releasing a AAA game in today's marketplace; as the Zero Punctuation review of the game aptly put it, "With all the expensive golden pixels modern graphics have to be built from, there just aren't enough hours in the day or memory on a disc to have a game as big as Deus Ex 1, whose engine was basically fashioned from polystyrene and sackcloth." And I know I've hyper-focused on the game's failings, but that's because the "professional" critical media's response to the game when it came out was pretty much nothing but this:
 But it's far from a bad game. It's a very enjoyable, polished and well-executed sneaky-shooty-hacky thing if you don't mind those elements being somewhat dumbed down, and don't mind that the story sort of abandons character development about halfway through. And just generally don't mind that it's not Deus Ex, and we'll probably never see another AAA game quite like that. I thought it was easily worth playing ... but I'm VERY glad I paid $7.50 a year after release instead of 50 bucks new at retail.
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