This game is a good idea, but poorly executed. Even though there are many ways to get theough a level it still feels very linear. There are quite a few graphical glitches, such as when you are jumping and grap a ledge it leaps you foward if you are not quite close enough. The graphics are quite a bit behind the time, so don't expect Mirrors Edge, Crysis or CoD 5, particually in the lighting department.
This game has a nasty habit of crashing, and after the first level checkpoints are quite far spread. This means repeating the same level many time. This also applies if you die (by missing a jump or being shot by a shotgun at point-blank).
This game plays alot better if you have an xbox 360 controller for the PC as there are some glitches with the mouse movements. I totally agree with the 3.5 out of 10 rating from gamespot. The voice acting is indeed poor and the cutscenes arn't up to much either.
For the most part the AI just stands still and shoots at you, though they some times have pre-programmed actions such as sliding down a wire.
This game seems to be intended as a cross between Mirrors Edge and GUN, but it does not live up to the excellence from those games.
The story line is marginally interesting, but not enough to cover up the poor mistakes. About the only thing which I found cool was in the first level when I had to climb up a long path I did it almost perfectly in sync with the computer character, which looked pretty cool (smashing through a window feet first together).
All in all, a very poor game which should have been released two years ago after much more testing.