Deus Ex: Invisible War (DX2) is game that combines 2 and maybe even 3 genres, the main and most obvious 2 or action and RPG, however, in some aspects it is also an adventure game. In the original Deus Ex you played as one J.C. Denton, a bio-modified super human/cop/spy. In DX2 you play as his nephew. At the beginning of the game you choose the characters sex and skin color. The only thing that makes a difference in game play is the sex of the character, and the impact is really not that much. So let's just discard that.
The game starts with and amazing video of the Tarsus academy in Chicago being incinerated. At the beginning you don't really know who attacked the city, whether he was after you, the Tarsus academy, or he just doesn't like Chicago. All is made clear later. The entire story is like opening 'Pandora's Box', one conspiracy after another is revealed. That is the only part of the story I am going to reveal.
Early on you get to choose your Bio-Mods, these are essentially your skills. There are ones like hacking computers, x-ray vision, cloaking, and so on. The skills can be upgraded or taken away to add different ones. Also, you can buy black-market mods, which unlock what are usually more useful functions. These skills you get can dramatically alter how you will proceed through each mission.
The weapons are only OK, there isn't really a huge selection of them. The basics are sniper rifle, sub machine gun, shotgun, flamethrower, and pistol. However, there are a few heavy weapons. Each weapon can be upgraded with two additional parts. Though you will find out that the best weapon is the sniper rifle with a silencer and power upgrade, because it means one shot kills. All of the weapons draw from the same ammo source; each weapon uses different amounts of ammo. However, ammo is scarce and you will need to conserve it and make every shot count.
There are 2 main factions you can work for; the WTO which you worked for in the original DX and now 'The Order,' which is a radical church who wants to stop the bio modification of humans. You can choose to work for either of the two or you can play the middle man, the game doesn't punish you for doing both missions. This is one of the downfalls of the game, because no matter what side you choose there is no light or dark side. The only plus you get is that there are 3 different endings depending on which path you follow. The missions range from the usually go kill this, to go and get this information, to destroy that coffee shop's supply of coffee.
The graphics, physics, and sound in this game are phenomenal. Throwing bodies against walls just to see what position they end up in is a lot of fun. However, boxes and other things you can pick up all seem to be the same weight, and can be thrown the same distances.
Overall Deus Ex: Invisible War is a solid game, it is short put packed with things to do, the average play time with all side quests included is about 16hrs, but because you will want to see all the endings it has tons of replay ability.