About the cast
There are many familiar faces in this drama, not sure if it's because I've been watching dramas for soooooo long or just... ye but don't worry the acting is fine.

About the plot
I think it's quite obvious that the author(s) don't want you to know the murderer that quickly, so they keep shifting your attention to different people first and slowly eliminate your suspicions.

About the characters
Sometimes Kwangsoo's character is logical and smart. Being pegged as the smartest/genius boy or whatever though.. Idk. There are times his character doesn't live up to his nickname. Well, I'm a fan of Yul and I think she's hella smart for a kid if there was a kid like that in real life... wow I will be scared. (maybe I'm just sheltered af AHAHHA)