<God mode enabled>
This brings me back to my sim city days where my sole purpose was to build cities I could unleash hell on. Very fun, glad to see it.
Anyhow, you asked for specific unfiltered feedback so here it goes.
My main issue with the game is that it is very difficult to tell who is alive and who is dead. I feel like either removing the dead bodies, or more preferably adding some sort of highlight to all alive islanders would greatly improve the games clarity.
Tiny critique: you can't see bottom island if you're not all the way zoomed out. I would add some empty map below the bottom island so player can move the camera over it without zooming out.
The meteors took too long to appear on screen at all which made me question if my input was registered, and they were very unpredictable which made me not want to use them even more. I would have preferred them to just hit a big circle around the area where I clicked, especially since they were expensive to use.
I feel like the tornado was a little bit missed opportunity, instead of just doing damage it would be really cool if you could use it as a position control thing, pushing survivors together or into the water so you could finish them with sharks and meteors.
If I was redesigning this game, I would reverse it in the sense that it wouldn't be a race to kill every islander, but you would have a specific amount of every catastrophe and your score would be how much damage you managed to do with the resources at your disposal.
Anyway I had fun unleashing the heavens on these guys.