I came across The Castle in the Mist on a middle grade blog I subscribe to. I try to read a variety of middle grade books now, since that is the category most of my writing is targeted to.
The Castle in the Mist skews to the younger end of the MG audience. It did not have a strong plot, and the characters did not have firm goals to work toward. The characters did not seem to undergo any internal or external changes over the course of the book. The writing was okay, but descriptions tended to be overdone.
For the reasons above, I gave this book three stars on Goodreads, rounded up from 2.5 stars.