This is an idiosyncratic five-star rating on my part. The plot is odd and meandering, almost as if the author was improvising it while writing, and the prose is workmanlike at best, and stiff and awkward at worst. On an objective level, it's probably a two-star book -- maybe three stars because of the illustrations.
But in its warmth and open-heartedness, this book totally won me over. It reminded me of when my dad used to make up bedtime stories for me when I was a child, and I was willing to simply give myself over to the world of Jasper Hedgehog.