I was very surprised!
The movie unfolds in a not distant future, 2044 where the only real technological change we've seen is solar panels on old cars. There is a wild west feel to it as clearly society has broken down to some degree, at one point a man guns down another in the street, but we are given nothing about that, which is refreshing.
The main character is a Looper. He isn't a time traveler at all. He waits for a contact time, when he gets it, he shows up with his gun and waits. Suddenly a man appears in front of him and he shoots. Killing the man, he can now dispose the body. That's the gist of the time travel. Criminals in the future can't get rid of bodies very easily so they send them into the past to be disposes of. The target/body shows up with silver cased on his back, he's killed an the silver is the payment.
The rub is the looping. Whenever a crime lord wants to close a loop, he sends the future self of the Looper back to be killed. The Looper knows his loop is closed when there is gold on the body. He's been retired, he can enjoy the next 30 years until his loop is closed and he too is sent back.
This is where it gets complicated and becomes a much see movie. Joe, the main character, gets outsmarted by Old Joe, who doesn't want to die. He doesn't want to die because he fears death, he doesn't want to die because he wants vengeance.
From there the movie takes a few nice turns, but some really great turns in the end.
I strongly recommend this movie. This is great science fiction without all the Hollywood bullshit, claptrap, thunderpows, etc.