Many people waited for this and I guess in the end there were poeple who liked it or didnt. I can say that the ones who liked it didnt watch a lot of thriller/action dramas like this and didnt find a lot of plot holes. I myself havent watched a lot of dramas of this genre but I found plot holes. It's not a masterpiece but I wouldnt say that it's bad.
The actors were able to play their character and even Nana who was inexperienced waws able to pull it off. One thing I didnt like was that the main lead was too cold, I know he would be based on what he went through in his childhood but I wanted him to speak more.
The OSTs were okay nothing wow about that.
It didnt really make me to love it but I finished it because I was curious and I can also say that I didnt mind the bittersweet ending.