As a fan of Park Hae Joon (the reason why I wanted to watch the movie in the first place) this movie definitely shows what a good actor he really is.

The plot is insanely interesting, there is constant action, a lot of gory and R-rated things, which don't bother me at all. I was born for action and this movie surely, gave it to me in the best aspect of it.
Of course the other actors did it great - Joo Hyuk, definitely did his job well (he got himself a new fan), as much as Hae Joon - even though this is not his first (the bad guy) role (see Doctor Stranger), same goes for Joon Yeol, who I like more and more with each role.

I would mark this as one of the best movies I have ever watched (nationwide) as this movie really shows, how good Korean movies can be (even though it's a remake).

If you love action, crime and investigation tangling with insanity - watch this movie and make sure to grab a lot of popcorn!