Yyup, that was entirely broken.
Should be fixed now, there's also a way to actually leave the hole!
Viewing post in Pico (Dream Diary Jam 5) comments
I think there are some bugs in the fish switching too. Switching directly from fish to pottomorph sometimes keeps the fish movement speed, and if I keep using items underwater I seem to sometimes end up as the slow fish-on-land instead of the underwater fish. None of this seems to stop the game from working, though.