I really enjoyed this, and who hasn't imagined things like that harassing you as a kid. Or maybe I'm just weird. Some of the words in the story were over-pronounced, particularly "little boy leg bone", almost like the reader was just terrified of fumbling the word, but it didn't really bother me, it just struck me as odd.
I like the separate creatures created for this, though I would've liked to get a little more description of the Grungies and whatnot.
It's been a few weeks since I read this, but if I remember right, I don't think I quite understood what happened in the end.