Trivia

When asked what they did to prepare for the film, Brendan Gleeson said he went to find a coat and Cillian Murphy said he grew a beard.

Although set in and around Dublin, most of the film was shot in London because it was cheaper.

Brendan Gleeson said the name of his character Perrier was a joking reference to his sparkling personality.

Writer Mark O'Rowe describes the film as "cartoon naturalism".

The film cast includes two Oscar winners: Jim Broadbent and Cillian Murphy; and one Oscar nominee: Brendan Gleeson.