Incredible gameplay depth and choice, philosophical and cerebral story make this a GOTY front runner.
The biggest strength of Deus Ex is the gameplay freedom that it gives you. Much like MGS4, there are actually multiple games within Deus Ex depending on your play style. It's amazing the choice you have in how to tackle each objective, while the game itself is deceptively linear. Talking to my friend on the phone as we were completing the same mission, we realised we were barely playing the same game. This is my perfect type of video game. The plot has a focused and set progression so the developers can tell a great story, while you have absolute freedom how to reach each fixed piece. It is a lot like Bioshock, and much like that classic game, the freedom of Deus Ex leads to intense, random encounters. Rather than the canned action scene of a Call of Duty game, you create your own experience and amuse yourself with the creative solutions.
Because you're given so much choice, the cutscenes feel like you've been handcuffed (I would have totally stabbed that Asian woman the first chance I got). Again, this goes towards being able to tell a tight and compelling story, which is another big strength of Deus Ex. Some games, like inFamous, give you what can hardly be called a question, let along an ethical question; kill everyone or save everyone. Others, like the Bioware masterpieces, give you fairly simple ethical ideas placed inside of complex scenarios. Deus Ex on the other hand asks a very complex ethical issue. The game provides you with multiple facets and positions of this difficult enhancement argument, without being heavy handed or forcing us to a conclusion. Although the game is science fiction, the issues are very relevant. This is real technology for the most part that could be right around the corner. I am very opinionated and I take a strong position on most everything, but I have never been able to come to a conclusion on the enhancement/technology issue. My hat is off to them for taking on such a complex issue and doing such a great job. Only one example is the Harvester area near the end of the game that was so twisted, it really made me squeamish.
Every small detail of the world reflects this maturity and philosophical complexity. I am usually fairly impatient when I play games, so whenever a game can make me stop to listen to conversations in the street or actually read the ancillary materials, it is doing something very well. I have nothing but respect for the backstory and texts that go into a game like Dragon Age. Unfortunately I never read any of it because, frankly, it's boring. Deus Ex accomplishes something that I have only ever really felt with Alpha Centauri (one of my top ten all time games), where most every little piece of literature is interesting enough, on it's own merits, to spark a ethical debate. Very few games even attempt to be this cerebral.
One thing I appreciated was how Deus Ex handled choice. In the Bioware games every decision you make has some epic consequence down the road. In Deus Ex, your choices don't affect the overall progress of the story in any meaningful way, but you get immediate feedback from everything you do. Even the smallest of choices are reflected in the changing world around you. I found this approach very refreshing.
There isn't much wrong with the game. I wish you could change the controller configuration. R3 zoom is a terrible idea. Great rpg elements and character progression. I wish the map showed shops. Load times are fine. Glitches are almost non-existent. The knocking out enemies hand to hand animations seem so much louder than the lethal takedowns, even though the opposite is true in the game. The AI is actually extremely good, making the game into quite a challenge, almost a puzzle at times. The music is phenomenal.
Admittedly the graphics are very weak and dated. But the design and art style help to make up for it. I still don't know why some characters have to suffer from repetitive and distracting ticks while they talk to you. Maybe they were trying to avoid the vacant, motionless zombie stare of the Bethesda games.
My only real criticism, and the biggest thing holding Deus Ex back from a perfect ten, is the dialogue. Not to say that it's bad, but recent video games have come leaps and bounds towards creating realistic, rich conversations between characters. The bar is set so high. In Deus Ex, the dialogue feels like what you would expect from a classic video game. Cold and stiff. Actually, I found that the whole presentation of the game, despite it's many strengths, felt a little bit stiff. This was almost a good thing as the game feels like an old PC classic rpg, triggering a lot of nostalgia for me.
Ultimately Deus Ex was just missing that last tiny inch for me to give it a perfect score. It is still a phenomenal game and my current front runner for game of the year.