Since this drama get a high score and good reviews, i started to watch it. I have not seen other adaptions (like the one made in 2016), or manga/anime version, but i really do feel disappointed.

1. Story: This drama should better be a movie: The first 4 episodes are super slow (the whole drama is slow). The story is being stretched too hard. Each episode last for around 25 minutes, why don't make a movie instead (or at least make it more interesting. This drama could have been done a lot better)? 5/10
2. The character's mentality, decisions, feelings are not well-described/expressed. The connections between the main characters and support characters are loosely coupled.
3. The cast: The main character acting is acceptable, but expression is quite poor. I understand that his character has gone through a lot, and he is a nerd himself, but the face expression is not really good. 6/10
4. The music is ok. Not special, but not disrupting. 7/10

Overall: 5/10.