During the first minutes, this discovery is not brought to life and Jensen has to be put on life or death surgery, because he lost the big majority of his body. From this moment on, the history of our protagonist begins trying to find the people responsible for this tragedy.
One thing that stands out in Deus Ex Human Revolution is the way the story is presented to us, allowing us to freely roam through it with our actions and decisions. It's a game of options and possibilities that adapts to what the player does on screen. Whatever you get to decide, will change possible futures but open new ones and vice-versa. You can actually kill every character in the game (with few exceptions), which makes the game really special, since you can actually feel the freedom to do anything.
Story-wise, I won't reveal much from the game, since most of what I could write about the game would feel like spoilers, but I can say that everything that happens in the game, is related to the main story in one way or the other, though at the beginning of the game it will feel like it's irrelevant. Another thing I'd like to point out, is how brilliantly Jensen changes according to your decisions.
Last but not least, the persuasion system deserves to be pointed out, since during many conversations, you will have to have the way to persuade people for them to give you the information you need, and this is done by getting to know the personality of each person so you can give an appropriate answer. And even if you end up badly with someone, you will always have the chance to shoot them so you can carry on.
Gameplay-wise, the game offers different routes to take, one way is to be stealthy and try to find alternative routes, which can lead you to the sewers, air ducts or even heights, using different abilities you will be unlocking throughout the game. This shortcuts are really useful since they will let you skip parts that would've caused you trouble if you had used force. Of course, this doesn't mean that you will always be able to stealth your way out.
Unlike Deus Ex, Human Revolution doesn't focus on illumination to ruin stealth, this time, it's sound, so the best way to approach without being noticed is kneeling down, though be careful, since there will be turrets, robots and cameras to make you have a hard time. Stealth doesn't only mean being able to sneak through your opponents unnoticed, it will also need you to pick-lock doors, hack computers and security systems so you can take on your enemies by surprise, and have their own security systems defend you instead.
If you fancy force, you will like the variety of weapons in the game, some are lethal, and some are not. From tranquilizing darts, gas grenades and such, you will be able to get your way through the game, but be careful, since this enemies can be waken up by their comrades, and they will wake up trying to find you.
On the lethal side, you will have a plenty of weapons to choose from. From revolvers, sniper rifles, assault rifles, semi-auto guns, heavy mgs, rocket launchers, laser guns and remember to add frag grenades and some proximity mines. Besides all this weapons, there are a bunch of special weapons that will be obtained during special circumstances like a crossbow and many other weapons which I won't spoil for you.
Animations in damage, and the overall feeling of this weapons, is really well done and will leave everyone with a good taste in their mouths. Combat in general is really well balanced, giving us a rechargeable health system, but you will be really vulnerable to other stuff like exposure to fire, or sniper rifles, just to mention some. Speaking of this animations, there will be times where you will be able to sneak up on your enemies in which if you melee, you will see a pretty assassination combat scene, and as pretty as they are, do not abuse them, since they will use lots of energy and it takes its time to recharge.
The game will never force you to use one gamestyle over the other. You will decide the way you want to play, and you will spend points in abilities you see fit to your own type of gameplay. This system will let you unlock subsystems in Adam's body, they will unlock through experience points, which can be gained by killing enemies with headshots, melee or any other way you fancy, or through Praxis. Some abilities are more useful than others but they are all well balanced and you won't feel like you took the wrong way with some abilities.
Visually the game is no eye candy. In fact, some of the models, textures and animations you will find in the game look like taken out from a really old game, but there are others in which the game comes out like a true champion, in which I would like to mention, the environments, the amount of stuff you can grab and manipulate and the great variety of places you can visit. One can see the amount of work placed on some areas of the game, one that definitely stands out, is the soundtrack, which is pretty minimalistic, but it can't be helped but to be noticed because the amount of quality in it is astonishing. It's not much like the music in previous games, but its definitely good.
One thing I disliked about the game, was the loading times. Some of them are specially lengthy.
In conclusion, Deus Ex is not a perfect game, in fact it is far from being one, but it's good to see an old franchise finally getting the respect it deserves. It managed to deliver the quality and essence of the original Deus Ex, and the aspects that were changed, are high quality. The game has a great story, good character development and overall, the game will keep you on the edge of your seat.