This is purely a city builder game with some exploration and resource management, no combat at all.
The only negative thing I can say about it is that I would have liked to see a better balance between the propulsion systems you can add to your city. This is because as far as propulsion systems go, the fins are the only game in town once your city gets big, fins eventually give something like 20% propulsion (dependent on the size of your city) while any other propulsion system get you a meager 1% to 4%. This combined with the costs in man power and/or coal upkeep means the fins are really your only option.
Lift systems have a similar problem but its not as bad as the drive systems.
The game is not very long, you can finish it in a day or two.
You can easily change the cosmetics of the whole city with the touch of a button, which is nice.
Depending on the design of your city reorganizing it or parts of it can be a slight pain in the ass, this is because its a flying city and everything needs to always stay connected and there is a tilt mechanic for the whole city, luckily you can move buildings around at little cost and pathways are always free. All buildings can become completely free to move with the right research, which is a nice touch.