First off, let me just say I'm highly impressed with the quality of this game. The level of detail put into everything is fantastic.
Few things I want to point out.
First off, the difficulty is a bit high for a demo mission. It starts off incredibly simple and slowly builds to the point where it really becomes a severe challenge. I'm not sure if it's supposed to be random, but it seemed like every time I got down to 2-3 squadrons left, they would all cluster, and I would end up in a 2v15 air battle with the fighters and IA-52's. Then, after I defeated everyone suddenly the 2 "advanced aircraft" came out of nowhere and wiped me out in a matter of just a couple minutes. They tanked quite a few direct hits and were just far faster and superior to the SU-27 you gave us. Not to mention by the time I had gotten that far into the game, my aircraft had already seen quite a bit of damage. It just felt unnecessarily difficult at the end. If there was a way to restock ammunition, or repair up the aircraft, then I think I wouldn't have a problem with it.
Second, I've never heard of an IA-52. I'm guessing they're supposed to be a B-52? I thought it strange that you used SU-27's, F-14's, MiG's, but you seemingly made up the IA-52? Again I could be wrong and just haven't heard of it before.
Third, PLEASE INCORPORATE MOUSE CONTROLS FOR FLIGHT! I was trying to fly with my mouse at first, and when I realized you had to rely solely on the keyboard, I was pretty disappointed. Make it so that you can choose to fly with the mouse, and then give us a keybind to "freelook" around the cockpit or something. Would make it so much smoother and easier to play.
Other than that, I love the game. Very much looking forward to a full version. 9/10