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.

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

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

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.