4.5 stars. A cozy, cute, and really fun middle grade mystery. There was a lot of enjoyment in reading this book and I sped through it. It has great winter vibes and pulls off the closed room mystery style with great finesse. The characters are quirky and intriguing and the entire plot moves fairly seamlessly. I loved the mix of fantasy and role-playing games into the plot as well. It really made things feel light and fun. The adventure and the protagonist were both very well-written and I'm really glad that there are other accompanying books. Greenglass House is just a cool place with a cool history and I'm very much ready to read more.