To the point:
I quit playing after failing the 5th mission, "sharks in the water" several times. True, I have little patience, especially for this type of absurdity. There seems to be a lack of difficulty balance, IMO. Also, you cannot upgrade or customize the helicopter and landing the thing is more difficult than it should be. You have to wait for a missile to find its target before firing off another which I found aggravating. I found myself NOT having fun and I really don't see the purpose in playing a game that I don't enjoy. Maybe the game gets better after the 5th mission, but I'll never know and don't care.