This adventure has very charming art and a cute concept. I love the idea of substituting larger monster variants to account for the shrunk PCs!
I found a few aspects of the layout that could be improved to make it more usable to a GM. I think this could easily be condensed into a one or two page dungeon, especially since there are no unique monster stats required and there are only a handful of areas. There are several ways to use the page space better. The page numbers are the largest size text on each page but they don't seem to be used or referenced at all. It is also strange that half a page is devoted to a refuse table without any interesting interactions in the results. Searching through refuse can be fun if there's something interesting/unique to find.
Besides using space more effectively, the utility for a GM at the table could be improved. The room keys on the map are not used anywhere besides on the map itself. Looking for a location description requires a finding the number in the map legend, noting the title, and flipping through the text to find that title. This could be as simple as reading the description directly off the map (for a one-page dungeon), or following the numerical key directly to the description.