The graphics, music, and presentation are good.
I feel like this game demo is missing some challenge or conflict that requires me to invest time into getting good at the game.
I would like to have seen something like hunting for fish by chasing a shadow, scaring away a fish if the boat moves too fast, the mermaid requesting a specific fish, etc. Something that requires use of skills like observation, identification, navigating a world from a map in your memory.