I've tried many airplane games, and I still think this one is the best.
I beat it about 3 times, unlocking new planes and weapons each time.
It has realistic looking graphics, great controls and AI, and tough challenges. I must have played one level about 20 times trying to fly my plane through a tunnel in the side of a mountain, crashing every time. I thought it was impossible, but after a while i was able to do it. After that, I could do it every time. You must practice at becoming a better pilot before you give up. Some missions take a few tries, and others you can beat in one shot.
It's been a year since I played it, and I would play it again. I don't have one complaint about it. It's perfect. It's just not as realistic as Flight Simulator or IL-2 Sturmovik, but its way more fun.