I loved the player sprite and colorful environments. The gated progression was quite confusing but definitely inspired me want to explore, which is what the purpose of a demo is so I can barely fault it for that. However, I wouldn't have included unfinished areas in the screen shots, that confused me quite a bit.
The sound was especially well done and matched the theme and character of the game nicely. I love those pitch bends in the melody channel. Good sound design overall.
The title screen, while good, lacked the same polish that the rest of the games visual's possessed. The bookshelf motif is wonderful and works well for the game, but the logo lacked the same charm when rendered as simple line art. I had trouble remembering the name of this entry , which could be due to the logo, or the poorly named rom file submitted (acronyms don't work in a big list of roms, hint hint).
These criticisms are only meant to be helpful, I am highly impressed with the casual world building on display here and I really hope you continue development. This is a wonderful game.