Fun idea with some very cute art! I had a bit of trouble figuring out what I had to do, before I realized that I was in a safe zone, and that this wasn't the actual gameplay I was playing yet. So an indicator of where to go, just to get me started, would have been nice. I thought it was a bit superfluous that I had to press E to pick up scales, and not just move into them. I got to day 5 or something on both my tries, and both times an evil fishy was lurking just behind the transition door, instantly ending my run, which was a bit of a pain.
That being said, I love the idea of a undersea dungeon crawler where you expand the places you can go, as you go. Overall good effort and nice execution!