A nice game that is ruined by a couple of insanely difficult missions.
Basically there are two levels of difficulty for this game: Training and Realistic. Veteran has no big difference from Realistic. "Training" should be just fine for every player, but the genuine pleasure in this game is to try to fly the helicopter in the Realistic mode - that's why we want to play this game in the first place, right? :)
Graphics isn't its strongest point, no excuse really for a late 2010 game, it could easily pass for a 2006 flight-sim game running on Windows Vista, but on the other hand, operating a helicopter is a feeling like very few, and no better modern game to experience it than this one. Also I liked very much the music theme of this game! In a way it reminded me a lot of the "Uncharted" tune. Very catchy.
Co-op mode works very well in this game. The one player flies the helicopter and the other operates the guns. I didn't try it with anyone, but tried to do it with a second controller, and for as long as I could play it this way, it seemed really enjoyable.
As I said in the beginning, you must practice a lot of hours/days to able to make serious progress in this game, but once you got improved the feeling is very rewarding, naturally.
This game obviously isn't for anyone, but every combat flight-sim fans, or gamers with a mild interest in this genre, should surely try this game.