Using a gunship is always fun, and squishing large groups of bad guys is satisfying. I think adding RTS elements was a good idea, since just a gunship mission on its own for a full game would get a bit repetitive without it.
As for my issues:
-Enemies spawn a bit too fast. The main issue is vehicles; you have limited ammo and Sabots seem finnicky, so I ran out of sabot ammo before the end of the mission despite being fairly conservative with my shots.
-The RTS is a little basic. I don't need a lot of granularity, but something more than "move there" would be nice.
-The three missions available in the demo all have the same objectives. Mission variety would be nice.
-Anti-air will spawn randomly, often on the other side of the map. Given your turret has a travel time, they almost always get a shot off before you're ready to fire at them and it distracts you from what you're doing for a good bit.
Still though, it's a fun little demo, and might be a fun game depending on the cost.