Why is this movie so underrated, I can't understand. It is a superb film: it is very cool, but ironic on itself at the same time, letting every people enjoy it (the ones who are not keen on the coolness itself only, too). It has a good sense of humor, sometimes nice, sometimes dark, sometimes grotesque humor. It has excellent action scenes, but not much enough to be boring. It is dramatic, but just as much as necessary. Of course, there are lots of similarities to movies like Bittersweet Life or A Dirty Carnival or Sympathy for Lady Vengeance. But it doesn't matter, because inside the texture of the movie - or should I say the "world of the movie" - everything fits perfectly: I daresay that No Mercy is maybe even more coherent and "harmonic" than Lady Vengeace (which is also an excellent movie) and because of this - better. Maybe if this is among the first Asian movies you see you'll find it weird how they change between the funny and light and bloody and dramatic (and so on) scenes, but if you're into Asian movies (Korean in the first place, because they have a distinctive aura), watch this by all means!