The film never really builds up to much, save some surprisingly violent scenes. With only two actors really showing off any skill (Buscemi and Hoffman) the film often seems a bit cardboard like. As for the 'abrupt' ending, there isn't really one, although the ending does seem a bit crappy as Bill Bathgate couldn't be so lucky that he manages to a: walk out just before the shootout. b: have $17,000 given to him just before he got grabbed. Lucky man my ass, if this is a true story.
Review of Billy Bathgate
