First of all, its a greate Game, okay the Bugs espically the Crashes need to be fixed then its really great.
Second, is my Suggestion i think the Buildings need much more Less HP it just need to long to destroy a single building, since there are so many Skirmishes in the Campaign it need a little bit more fast paced.
Third the Air Units dont feel like Air Units since they very slow they need to be faster aswell. Maybe think about a overall Speed Increase of all Units.
That was it sorry for bad English
Greetings Move