Not bad
The best weapon for the combat missions is the M16 because there is no delay between shots, it doesn't narrow your vision to a small scope, and it holds a large clip. You can easily kill 3 enemies without getting hit. The best weapon for the sniping missions is the barrett or the dragunov.
I detected a slight problem in the opening mission. The guy who shoots at you from behind glass doesn't break the glass.
Also, on the mission where you spot the guy in the alley with binoculars - if you pull out your gun then he will start to shoot you, and then after you kill him you are stuck. The mission does not end and you have to restart.
Also, once my game froze when I was entering a scene, and I had to start over.