Without upstream expectations: A good movie

I do not know how the film came to my wish list, but I looked at him without any expectations, such as that he "like Sin City" and should be found 'him amusing, entertaining and well done.
Actually, I wanted to give him only four stars, but now that I write these lines I think to myself "why not five stars if it was amusing, entertaining and well made?". So five stars!
One question remains unanswered: Why FSK18? A couple of fight scenes, a few bare torso, a couple of shootings. Nothing that had not already been there in a FSK16 movie ...