I bought this on a whim because I like sci-fi and Bruce Willis and it was comparatively cheap. I hesitated for a moment because it's written and directed by Rian Johnson (I've yet to see something of his that I like, and don't get me started on The Last Jedi). Regardless, I took the plunge, how bad could it be?
First off let's get the positive stuff out there. Solid acting all around, great visuals and effects. Johnson can at least construct interesting scenes even if he can't tell a compelling story. The initial concept is interesting. That's about it. Everything else about the movie sucked, cliché plodding story full of plot holes and convenience writing.
Plot holes. Logic conundrums are expected in time travel movies, and some get away with more because they are light-hearted like the Back to the Future trilogy. Looper however plays it very serious and dystopian. That's only a problem because the holes are practically gaping. For example, in the future time travel is used by the mafia to dispose of people by sending them back in time (still alive) to be dispatched by loopers. Apparently, forensic science is so good in the future it's impossible to get away with murder, but apparently you can disappear someone with highly illegal time travel tech and no one's the wiser. Ok. Then it breaks it's own rules when future mafia comes after Willis and his wife using LETHAL force! What was the point of sending your victims back in time still alive again? Then there is the ending, which is the typical kill a big bad from the future when he is young and defenseless paradox. The movie plays it like the Big Bad becomes the Big Bad because of Willis' vendetta against the Big Bad for killing his wife. Hence another loop. But how did the loop start? Without that information Gordon-Levitt's (aka young Willis) actions at the end may not make a difference at all.
There are other logic problems and paradoxes, and I could live with them if there weren't other problems. The film is slow and about 30 minutes too long. I had a hard time caring about the characters, except for Bruce Willis (but only because he is Bruce Willis, his character in this movie is definitely as morally grey as the rest of them EDIT: actually he's kind of evil, even if he's only taking his actions to save his wife and other loopers). The action is sub-par, and I didn't know that a future with telekinesis, time travel, and flying sportbikes could be so dull.
There is some neat stuff to be sure. In fact the whole movie is a collection of neat ideas that I think just weren't fleshed out properly, and wrapped up in a completely mediocre story. I wouldn't buy it if I could loop back, but at least it was cheap.