The success of this book -- like almost all of them for the pre-reading set -- comes down to the effort put into it by whoever is reading the book to the child. If someone gets into the rhyme, oohs and ahhs over the art just right, and has a lot of fun with it, I can't imagine how a kid won't either.
Zvolon wrote this to help her granddaughters deal with the trauma of having their nails trimmed -- which can be a struggle for some kids, I know. So Zvolon came up with a way to turn the experience into a game into something fantastical. She tells a very simple rhyming story about Nils overcoming his fear of getting his nails trimmed with the help of a game. It's a neat idea told in an attractive fashion.
The art is something else -- if it doesn't make you think fantasy, nothing will. Rotem Lots-Zaiden doesn't illustrate this like any contemporary children's book -- it feels like something that came out of the 1970's -- maybe early Sesame Street animation. This is not a bad thing, I think it serves the story pretty well, and the strange features and interesting colors should keep the attention of young readers.
I honestly never thought I'd read a book about trimming nails, or helping someone through the struggle of it. But now that I have, I can't imagine a better one on the subject. This is good stuff, and I hope it helps some kids.
Disclaimer: I received a copy of this book from the author in exchange for my honest opinions as expressed above.