The voice acting, sound effects, and childlike art style are so great! Simple, but very effective at setting the mood. I especially liked the funny sound when you catch an electric eel! :)
Maybe it's just me, but I had some difficulty telling which direction the seagulls are, even with headphones. Maybe the volume difference of left/right channels could be exaggerated more?
I encountered a bug on the second day, where Mariana sailed off the right side of the screen. On my first playthrough I caught enough fish and heard the voice lines saying to return home, but I started moving right instead. If I pressed left I stopped moving, and when I let go I started moving right again. On my second playthrough it happened after my third fish. So unfortunately I was not able to finish the game because Mariana has decided to sail around the world. Good thing she is such an experienced sailor and fisher! :D