Cool idea, I definitely think its biggest drawback is one, the UI is clunky so placing the islands could be smoother (like a transparent preview of where it'll place) and being able to delete individual islands. Also the platforming is left to be desired, and I think that's where most of the expandability is going to come from, because ultimately this is a puzzle-platformer. Because this is 3rd person, I'd recommend opting for a standard 3rd person camera that can be rotated the mouse instead of the button turning. But that's just my personal thing.