I admit it took me a while to figure out how to buy allied planes, I complained on range or whatever the vox is called and somebody asked me if I knew how to buy planes. The problem I had was I didn't have the box for allied planes checked. Or something like that. It doesn't take much, just ten AI kills to get a wildcat, and the FM2 isn't too hard to get once you have that. Personally, maybe because of the fighting style, the constant spawning enemies or something but base model zero seems to be the easiest plane to get kills in period.
The free for all/country thing is unexplained so it isn't clear whether or not killing the purple people is ok or not. In my opinion everybody should be red with maybe something to indicate that it is a person not an AI. The flag that humans get on their icon kind of ads to the confusion as to whether you are supposed to be shooting at "foreigners" or everybody.
I don't know if the AI gets bettter the more you play but the dive bombers are becoming ridiculous.
I think its fun, I wish you could land, the AI seems to get landings.
I see that you started adding AI in the Match Play if you spawn out on a runway heading. They seem to take a long coffee break between launching and It might be nice to have more than one at a time, I'm also not sure why the WW1 planes are in rotation likewise the Mossie Bomber.
TLDR: Maybe a little work on the UI so people know what is going on and more obviously how to upgrade planes, Maybe start with the f4f instead of the P40.