The visuals and audio are great.
What I'd change:
- While it is atmospheric, I didn't have a clue of what I was supposed to do. I assume you need to do something the boat when you find a key to it? But I can't find the key. There could be more notes or similar cues in the start of the game in the first path that could give vague hints of what to find and where you could find it.
- When you are tired, the closing and opening of the eyes feel slightly annoying to look at even though it does add emphasis to the feel of being tired. I'd prefer if it was a simple gradual whole screen transition to no vision and vision instead of the flickering.
Bugs: You can get stuck on the rock next to the chair on the hill that leads to the river.
Good job with the game!