An engaging story-telling experience, unusual gameplay, and hours of enjoyment, though it also has it's issues.
Although Deus Ex may appear to be just another first-person shooter, it's truly an RPG at heart. This is one of the true action-RPG's, rather than some other genre with RPG elements tacked on. Instead of being instantly skilled with any weapon you find, you must first spend the required skill points in any of four possible areas: melee weapons, small arms, rifles, and demolitions. There's also a variety of other skills available, such as lockpicking and medicine, which increase your ability to perform certain tasks and use various kinds of equipment.
The story at the center of Deus Ex is expansive, and the cyberpunk romp will lead you through New York, Hong Kong, underground bases, Area 51, and more. The well-written intro cinematic leads you in to the setting: a mysterious plague, known as the Grey Death, is ravaging the world. The cure- Ambrosia- is in short supply, and a sinister gambit is being played out to manipulate the world into the control of a mysterious organization. The game begins with you searching for a shipment of Ambrosia that has been hijacked by terrorists, and soon leads you through a twisting plot that raises interesting philosophical questions, and shows true intelligence in the writers.
However, the game is not without flaws. First, it's ugly. Although the drab and dingy aesthetic is very fitting for the cyberpunk genre, it's not very well done. Other cyberpunk works, such as Blade Runner and Ghost in the Shell, create very compelling worlds; they have personality. Deus Ex's uninspired visuals just feel lazy. Characters are well-modeled and the textures for some NPC's look amazing, but they all animate stiffly and dip into the uncanny valley at times.
Not helping the characters is their acting. Voices range from sub-par to terrible, and each NPC incessantly repeats one or two lines of dialog every time you walk by. A particularly annoying one in the Hong Kong levels had me tearing my hair out every time I had to visit her particular area. The lines themselves aren't poorly-written, but the fifteenth repetition of "I'm so HUNGRY..." by bums in the New York levels will make you wish very dearly for the ability to kill them without consequence.
However, the game's consequence system is one of it's greatest strengths. Other characters react to your actions in the game world, sometimes in startlingly life-like or unexpected ways. If you don't rescue a hostage in an early level, the bonus for doing so instead goes to the soldiers who rescued them after you completed the main objective. Trying something unusual merely for the sake of doing so can lead to unexpected optional encounters, designed especially in case players strayed off the beaten path. It's a very interesting mechanic that rewards creative players and lends itself to replay value.
In addition to upgrading your various skills, you can also augment your character with various nanomachine supplements. There are only so many slots that are compatible with certain kinds of augmentations, so you can be left with hard decisions that influence your play-style for the rest of the game. Rather than limiting you, however, this allows you more freedom to make your character truly yours- more so than if you were able to acquire every augmentation by the end of the game.
The game is relatively easy, though. The pistol you start the game with can see you through most human enemies, and there is a very powerful weapon near the end of the game's second act that makes all but the toughest encounters a complete cakewalk. Depending on what kind of gamer you are, this can be a good or bad thing. Deus Ex's story is so enjoyable, however, that it doesn't especially matter either way.
Overall, Deus Ex is not an incredible game, but it is certainly a unique experience. Although flawed, it's high points are so amazing that it's easy to look past the poor voice acting and bland graphics to see the diamond in the rough.