I was fortunate enough to get my hands on this demo, even though it is broken and does not take advantage of my Q6700 8800GTX 4 gig rig. However, even with all the bugs and performance issues it is still better than anything I have ever played and a wonderful treat to get your hands on. I played that demo over and over again and before I knew it I was playing on delta (hardest difficulty setting) and managed to kill everything alive on the map. Even though this demo does not take the full potential of todays high quality gaming rig, it still looks beautiful.
This demo is also a curse -- I can't look at any other game anymore. I tried to play Bioshock after my love affair with this and I turned it off in disgust. This demo has corrupted me in a certain way I don't think I can take any game seriously that was released pre demo. Although the AI is buggy they are still responsive and challenging. They run for cover, they hide, they throw grenades at you, and they even shoot the area where you've been which can sometimes drop a palm tree on your head. This is due to the Crytech engine which allows you to shoot off every single leaf of that palm tree. Almost everything is destructible in this demo. There are multiple ways I could approach each objective -- not just 2 or 3 ways, but dozens of ways. The map was truly open ended and it never gave me a feeling of claustrophobia like other games did (yes I'm looking at you Bioshock).
For a demo it is very generous -- you can wield 3 different weapons which are modifiable on the run. If you prefer sniping people you can do that, if you prefer to run and gun it you can do that too. If you prefer blowing up a vehicle by shooting it in its gas tank, cloaking yourself, disappearing from their sight, then watch the whole thing blow up, you can do that too. If you want to hijack a vehicle and kill everyone via its mounted assault rifle that is an option. If you want to drive into a building, crash through the wall, and blow the whole house up with everything and everyone in it you can do that as well. This is the first time in gaming history that you can actually feel like you got dropped off on an island with a high tech nano-suit, a weapon, and a mission, because everything is do-able in this demo. I can even hijack a boat, swim by an island and kill everyong on it, plus blow up their shacks by tossing a grenade or an exploding barrel. Everything about this game is amazing, even the water physics. In my opinion this is the closest you can get to an experience so real you forget you are playing a video game. Oh and don't forget, this is just a demo -- imagine what the finished product will be like...