As much as I liked Princess Celie, the best character in this book is Castle Glower. The Castle is magical and probably alive, with a real personality. I love that every Tuesday it decides to have a change and rearrange the layout or create a new room. 

I enjoyed the book and read it in one sitting. It did at times feel a little too silly, with both the royal children and the adult villains doing things that didn't make any sense, which is the main reason that I didn't rate it higher. Despite that it was very entertaining and I would happily read the rest of the series. 

I did at first try listening to the audiobook, but I wasn't keen on the narration so found it much more satisfying to read the physical book.