This game is really pretty and I love the dynamic music that changes as you grow larger.
Some things I liked:
1. There are 2 or 3 layers to the environment and skybox, meaning your play area is able to accommodate you at all sizes
2. The wavy animation on the fish is awesome! Reminds me a lot of Abzu
3. The music when you are large is hilariously epic sounding with the choir singing like you're freakin' Sephiroth
Couple of things that could help make it a bit easier to play:
1. Options for mouse acceleration and y-axis inversion. It's really sensitive by default with my mouse settings making it very hard to aim
2. I didn't think I could eat the puffer fish at the beginning because they were bigger than me. Maybe something that could be explained better in the description? Or indicated somehow in-game?
3. Charge meter and cooldown timer HUD/visuals for dash mechanic. Also maybe a little line showing the exact direction you are about to dash in so you can aim better (since you're about to commit to heading that direction for a while)
Screenshot of the size I got to :P