It's a little too simple and a little too short to recommend. It's OK when you're playing it, but you don't get a lot of value for your money unless you got it as part of a bundle or at a steep discount.

The main innovation is that you have a flying city. It's a city builder where you're roaming the landscape, constantly scavenging food, water, and resources. Most city builders have moderately complex simulation of the citizens; Airborne Kingdom doesn't, beyond having them walk to construction sites when you build something.

You don't need to take much care when planning your city. There's one (1) building that has an area-of-effect that affects housing, and a bunch of industrial buildings that have a negative effect. Which means city layout is mostly just "houses cluster around faith buildings, don't build nasty industry near houses."

Production chains are just a single step each, turning raw materials into finished items. Mostly the build cycle consists of building enough housing, building one or maybe two production buildings of each type, and building enough Lift and Propulsion buildings so your city stays aloft and moves at a reasonable pace. There's just not much too it.

It doesn't help that you need to complete quests for ground-based cities, and those quest are almost all "go find this object for us." Flying scavenger hunts get old pretty quickly.

It's not exactly a *bad* game, it's just ultimately not that interesting.

The idea is not bad, but it's not fully developed the neither as a city builder: it lacks depth; some buildings where never a necessity because when I got it I already had better ones; resources are not that scarce to justify all the upgrades of production cost; using workers as a resource is ok, but you cannot reassign them without destroying buildings which makes no sense to me, etc, or as a rpg: ok, it has missions and you look for some things on the map ... just that.
Art style is ok but unrefined, some customization breaks the art of the game which is unsettling. In some scenarios the lack of contrasts makes things difficult to see and distinguish.
Finally the game feels unrewarding, I spent half a day playing it to the end and I feel nothing, no satisfaction or even frustration, it's just annoyingly forgettable