Really enjoyable! Good progression loop, fast enough to keep you engaged, but slow enough to be somewhat challenging. I enjoy the sound design a lot, especially when you've got pretty far into the progression of the game and you can hear all of the sounds going off together; I appreciate that they aren't too noisy or overstimulating as well. 

Only thing is I think I would definitely appreciate a feature that would allow you to zoom out once you've reached the larger islands so panning across becomes less tedious. Other than that, I have no real critiques, it was very fun!