Viva La Human Revolution!
This game aside my knowledge of the Deus Ex universe is fairly minimal.
At least once a year I tend to start up the first game, play through the Liberty Island opening and stop not long after that. I don't know why I stop there. I don't think the game is bad at all. But I do.
I rented Invisible War once. Didn't have it long enough to make a lot of progress, but from what I'd played I didn't think it as bad as many others did. Even with fairly minimal experience with it, I'd take the original over Invisible War though.
In any event it's a good thing you don't really need any first hand experience with either to enjoy Deus Ex: Human Revolution. Got to love prequels, right?
I'm sure there's lots of references I didn't pick up on due to not playing a lot of either of the past games, but you'll have no problem following the story and that's why you'll be playing this game.
You probably already know the setup.
You play Adam Jensen, head of security for Sarif Industries - a big name in human augmentation. Early on Sarif Industries HQ is attacked and leaves you in a bad way, so naturally you get patched up with augments of your own.
And then you're left to find out the who, what, why, when and which of it all.
The trailers talked up being able to play four different game play styles.
Social, stealth, hacking and combat. But try as you might to stick to one thing, you WILL be doing others. Mostly.
You will be doing a fair amount of talking, naturally.
Conversation trees are mostly fairly linear though you will occasionally be able to influence minor changes through them and you can even acquire an augment to help you read and influence people better in order to make these changes.
Of course all these conversations are fully voiced and the main cast is done so adequately but there's a side character or two with borderline offensive accents and otherwise ear rapingly bad voice work.
Stealth I feel like is kind of pushed on you a fair bit.
I feel like you get more and bigger XP bonuses for sneaking around, using air vents and knocking dudes out then you do for just barging in and shooting up the joint which kind of discouraged me from indulging in any unnecessary combat.
Not an terrible thing because the gun play in this isn't top notch anyway and most of it can be avoided with the exception of a few out of place boss fights.
I understand the need to have Adam confront these guys in order to drive the narrative but making them typical gamey "boss" encounters with patterns and motions they go through is a tad off putting. I see no reason why they couldn't be like any other encounter, save perhaps a little stronger and with some unique weaponry or what have you. One could argue that would be more dull but to me at least it would be preferable.
Hacking is done via a mini game as you would probably expect and to begin with it's pretty tricky but dumping a fair amount of points into the right skill set makes it child's play and will get you into all manner of places and computers to read e-mails and such. Some messages just fill in some back story and tell you more about the world, but some will reveal important plot points sometimes hours before you would otherwise find them. Sadly this won't change any dialogue.
I knew spoiler removed from reading the e-mails but I guess Jensen was only skimming them because he was still surprised later on when spoiler removed.
So obviously Human Revolution has some minor issues but the game is fun enough, the world and story captivating enough that they are pretty easy to overlook. As I said I'm not familiar enough with the original Deus Ex to know whether this is worthy prequel to a game many hold in such high regard, but it's a great game in it's own right.