When i started watching this film i didn't have any expectations ... because i didn't have a clue what the film was about. So it could have been turned out pretty nasty; but luckily it did't! It was a really nice experience.
The first obvious thing i noticed was the professional work of the DP/director. This film is beautiful shot; lightning, camera etc. Sound and music were fine, but weren't very special but rather very solid. The second thing is the surprising good acting of the entire cast. There weren't any awkward moments. Everything felt very natural. And this is very important for the entire film because so much of the atmosphere depends on the performance of the lead protagonists. If they fail, the whole film might collapse.
A friend of mine said "crying fist" would be the Korean equivalent of Rocky. Well, i don't agree with this. The story of "crying fist" has much more content and value; discussing, for example, the issues and problems of people who lost their status in society is important and worthwhile. And, in this case, also very moving.
If you are interested don't hesitate! I really can recommend this one!