I loved this story. I loved everything about this story, to the extent that I'm not sure if I can even express how much I loved it. There were points in the story (like when the wolf appeared) that I expected it to change directions and become less awesome, but every time that happened, it just became more awesome.
I loved Monster (who kind of reminded me of Bing Bong from Inside Out, in the best way possible). I loved the overturning of fairy tale tropes, especially how the "Big Bad Wolf" was actually on Red's side in fighting against the much more realistic (and also much more mundane) evil of the abusive stepfather. In the Little Red Riding Hood fairy tale, the Big Bad Wolf is a pretty obvious metaphor for a rapist and/or kidnapper, but for someone like Red who has undergone real-life abuse, there's no need for metaphors and cautionary tales to let her know about the evils in the world, because she has a real-life villain in her life who abused her and abused her mother and maybe even killed her mother (that was the implication, right?).
I also loved Red and Ashley's relationship, which was close and loving while also being believably teenaged. And I loved the narrative voice and the tone of the story; usually stories told in the second person seem kind of gimmicky; it's a hard perspective to pull off well, but here it was done perfectly. And the monsters were wonderful. So was Tina Connolly's reading. I could go on and on about things I loved about this story; it was just so good.