The Roundup series is pretty interesting. New Story in each part with next characters and villains. But what I don't like is the decreasing reputation of villain.
Part 1 villain was tactical and adamant, Part 2 villain was the most scary psychopath, while Part 3 got the smartest villain. But in this Part, Villain lacked any presence at all. He kept the straight baby face, which is not very suitable for Antagonists. The Hero, Do Seok, is consistent but it's the villains who add value in the movie. The more cunning they are, the more fun it is to watch. Part 4 villain was just a fluke. He was neither a psycho nor intelligent. The only redeeming thing about him is fearlessness. That's his x factor, which is if you think about, is common in every villain. They don't fear hence they break laws.

Second was the choreography. The fight part was lackluster. Even the last fight looks pale in comparison to what Jang Chen did at the airport. So that was another let down. It was an okayish movie with not much of chase. There was chase but very mediocre compared to Part-1 & 2.