Since this installment of the series was set in the school, just like the first one, I had some of the same issues. Again, the characters are a bit shallow, and the since this one involves travelling through *multiple* doors, the world building for those worlds lacks some depth as well, and is a bit exposition-heavy. Confections is supposedly "Nonsense, but with rules", but what the rules are is never clear. I wasn't particularly invested in the quest. 

The social justice issue of this one (fatfobia) came up more naturally than in the first one, but is not really brought with any subtelty,  perhaps due to the more YA audience. I didn't enjoy this story as much as the first one (maybe I just dislike Confection too much) and think I would have DNF'd had this not been a novella.