The sci-fi, which stars Joseph Gordon-Levitt, Bruce Willis and Emily Blunt, tells the story of a killer who discovers that one of his targets is his future self.
Gordon-Levitt spent an extensive three hours in the make-up chair every morning of shooting in order to resemble a younger Willis. He has confessed that even his mother had trouble recognising him.
Blunt previously told Digital Spy that she was "over-excited" about Looper, explaining: "It's a very different kind of movie, very high concept. It's dark, set in a post-apocalyptic world and it involves time travel but done in a really cool way.
"I really like what Rian's done with this script because it feels accessible, it feels like maybe we are only 50 years away from being in this realm."
Looper opens in cinemas on September 28.
Watch Emily Blunt discuss Looper with Digital Spy below: