I listened to this as an audiobook and was absolutely caught up in it. It would be a wonderful read-aloud harkening back to an old-fashioned adventure fantasy story. But if I were to make a more modern comparison, it reminded me of The Tale of Desperaux, a lighter and less scary Stranger Things, and a dash of Dangerous Book for Boys or Daring Book for Girls.
It involves four kids, a dog, a brother turned lizard, a tyrant, a sea captain, and a beautiful librarian. It's a battle between good and evil. And, hopefully, the second installment is being worked on since I can't wait to read more.
Apparently, the physical copy has illustrations so I should grab a copy to look at them.