The background graphics have a wonderful spooky feel to it; I love the details of the trees. I agree with Rey in that the 160 x 144 screen is way too small. Scaling is allowed, so long as the right aspect ratio is retained, if you didn't already know.
The gameplay itself is more on the confusing side for me. There aren't any instructions present, so I'm not sure if I'm missing out on a certain control, but I got partway to a ledge that is slightly higher than my tallest jump, and found myself unable to get on top of it. I notice that I can stick to the sides of ledges, so I'm not sure if there is something present to get on top of there that I'm not aware of, or if it is a bug. For clarification, I've got a screenshot here.
Critters causing a headache is right! The music gives off a great spooky atmosphere, but the sound effects of the jumping enemies get annoying pretty fast. They're a bit on the loud side.
I did enjoy the narration over the game as the player progresses, however. It adds an engaging element to what is mostly linear gameplay (as far as I've gotten, anyhow).
So if there's anything that needs the most polish, it's: adding clarification on how to play the game, ie. the controls (which could just as easily be put in the game's description page here), and scaling the game to a bigger, more visible size. And if the controls are just limited to the WASD keys, perhaps you'd want to look into the ledge that I took a screenshot of, as I can't figure out how to get up there at the moment.