Hey,
yeah I could never get the swimming controls the way I wanted for that demo. there's no extra suit upgrade for that, it's just bad design :P.
And the digging--I've decided I'm going to remove digging. It's a good way to hide secrets, but having to put rocks down everywhere just sort of spoils the look of the game. beyond that, digging kind of messes with the core concept: you're here to observe, not to destroy. digging destroys.
I made the game in openfl, using haxepunk as my framework. mostly because I started with flash and flashpunk--I don't know if I'd heartily recommend haxepunk. haxeflixel is probably better.