I bought this as a present for my daughter (5) who loves it, better yet her elder sister enjoys reading it to her. It's opened plenty of discussions about what's possible in space... other than cakes!
What I will say is how disappointing the paperback edition is, so much of the vibrancy of the brilliant illustrations by Sarah is lost because of the choices made in the publication. It doesn't distract from the story, nor have the girls commented on the difference. In future I will most definitely purchase the hardback versions, letting all the illustrator's hard work leap off the page and really bring to life a most excellent story.