No pun intended - actually you could say killers too (or is it two?) ... more puns for you. The movie itself is not really that funny though. It is more a serious affair - I reckon if you have a weird sense of humor you may find certain things funny ... in a dark way that is.
If you are fan of Korean movies, I do not have to convince you - you already know that South Korea produces some really good movies. And this is another example of that. Sensibilities in some instances and certain things (the hitting especially) may feel foreign (no pun intended) ... but they add to the flavor of the movie ... and the stories? Well very well thought of and written ... and acted! And all the other things too of course.
Good production value, interesting characters - and twists to make your head spin. And I am being serious - still not everyones cup of tea of course ... but if you are not too sensitive, the movie will please you ... or whatever you would call it.