Joaquin Phoenix has been one of my favorite actors since starring in Gladiator all those years ago. He doesn't do very many films and I was surprised to see him in this one. This movie was not a blockbuster and was never meant to be one. It did, however, catch the eye of many people at various festivals around the world and won a bunch of awards.
Joe (Phoenix) is a retired military vet who takes jobs as a hired killer who seems to specialize in the rescuing of young girls who are involved in human trafficking (it isn't completely explained.) His methods are unusual and quite brutal and Joe himself is a very troubled individual, frequently suffering from lucid flashbacks of his youth as well as his time in the military. He doesn't seem to have a great deal of emotions, it doesn't even seem as though he takes on the rescuing of young girls because of any sort of moral high-ground, it is just something he does for money and is apparently very good at it because he is known as someone who will get things done.
I feel as though this movie gets overly good reviews from the press because it is artsy rather than being straight-forward. Phoenix does a good job (as expected) and overall the movie keeps moving at a reasonable pace to keep you interested. However, in my mind the movie's artsy methods rather than just telling the story, get in the way of the progression and at times you really need to pay extremely close attention just to know what is going on.
Overall it is definitely worth watching and I thought it was good. I just don't think it is as good as it is being touted on a bunch of different major review websites. I normally feel this way about films that win at Cannes though, so this is not at all surprising to me.