Dude, that's not at all bad, like at all. It's probably one of the richest games in terms of what you can do so far, GG.
As always here's some feedback: The game feels very polished in its UI/interactions (especially the card menu). The gameplay it's good, it becomes quite easy on the later waves but hey, balancing is hard (and frankly not even that much of an issue in a 2 days jam). Lastly, I think that it would have been better if the grid on the ocean wasn't visible during the waves, but only when placing islands (is was a bit hard on the eyes after 15m).
Anyway, it's very impressive. Good job and good luck :)