In single player scripting and team AI seem to be flawed to the point of being idiotic. On a number of occasions the teammates would run ahead like 2-3 meters and disappear behind a bend. when i proceed to follow them, some big nasty gets spawned and i have to fight it on my own, while my team is nowhere in sight. once i defeat the big nasty, i finally go around the bend and there they are, my awesome team.... sitting on their asses... where were they while i had crap kicked out of me? also, sometimes im advancing on the enemy and my team is sitting behind cover. after proceeding through a corridor or two and clearing out a gaggle of bad guys, suddenly my team magically appears right behind me. what kind of crap is that?!! also, the game suffers from something i used to see in older games where no matter how big is the group you are with, the enemy always starts to pick on you. it's like it knows that if they kill you there's a good chance youll have to restart the game :\
the other thing that bugged me is the limited colour palette. seems like the entire game is coloured with shades of gray or brown. say what you will, but it gets very tiresome on the eyes.