I didn't watch too many South Korean movies to be honest, but even after watching some great films like Parasite, A Taxi Driver, Mother,..., this film is still my favortie of all time.
The story is so well written, it started with some cliche criminal plot revolved around cocaine, drug but it impressed me when they brought children from poor family into the story. I was so moved watching how these children live and some even die, those things actually happen in real life and in my country (Vietnam), that's why I was so sastified seeing Won Bin's character killed them all, his action also came from the fact he really loves children, since his own kid passed away before the birth. From the opening with a small theft of a stripper, to the ending where the stripper's daughter has to say goodbye with the neighbor who is close to her like father, the script is a rollercoaster of emotion and well builded storyline, I totally love it.
The acting in this fim is tremendous. Won Bin transformed from drama MC to action hero was incredible, Saeron had her best role until now at the age of 10, and the villiains are on another level, the brothers and the Thai assasin stole the scene everytime they appeared, this film probably has one of the best acting in an action movie of all time.
I wasn't impressed with the music as much as story and acting but it isn't bad at all, still played its role nicely.
I watched this film around 10 times now, it's not only great film but also rewatchable film, believe me you won't feel sleppy even when you had watched it 5 times :)