This was really cool! I loved the artwork for the various fish types - some of them definitely gave creepy vibes when I saw them passing nearby.
Nice music too, it fits the game setting very well! Adds to the atmosphere, as does the darkness of the deep ocean.
I loved the progression of the chomp sounds, and the game had me curious to see where the evolutions would take me.
I made it to the end. Congrats on having time to include an ending! :) Very nice entry!