That intro animatic was stellar. It really set up the game well, but I couldn't work out what to do inside the pond. I thought there might be something at the bottom, and loved the way it got darker and darker, but couldn't figure the answer.
I feel like leaning on your storytelling skills might be the play here. Maybe he goes down and discovers a hole at the bottom of the lake, and carries on into more and more horrific scenes as the place gets darker sort of like The Descent, or a moody indie game! Whatever the plan was with the fish and minigame aspect, I feel like it would have distracted from the great mood you were able to setup. It put me in mind of frog fractions a little bit, and I'd love to see what the story of the rest of the game is!