There are no superhero type action scenes with people flying or doing acrobatics. Just some good old reality based gunfights, fistfights & machete fights. The kills were a little bloodier than most action/thrillers but it wasn't off-putting. The shootout scenes weren't exciting enough. It takes place mostly in Russia which I wish they had shown more of. It has a great score that really intensified the scenes.
Obviously you have to suspend disbelief when a bald man with a UPC code tattooed on the back of his head can't be found by law enforcement agencies all over the globe, especially when he isn't the only one meeting that description. The plot is pretty simple with a couple of interesting turns, some explained explicitly & some not. There is a woman in the movie & although she seems like the love interest she isn't. I was pleasantly surprised by how that sub-plot turned out. The movie would have been better without the "bookend" story structure.
It's an action movie so we never really learn much about the hitman. At first it seems like he is socially inept but he isn't. He is pretty normal, just focused on his job of killing people. Timothy Olyphant was great as the hitman, he is supposed to be an emotionless assassin but he occasionally injects some life into the character. I love his annoyed/angry look that he gets when he is about to hurt someone. He has a moral awakening during the course of the movie but because it is gradual, it comes across as being believable.