As a murder mystery film A Belfast Story delivered. Colm Meaney did tend to grumble his way through it a bit though giving his character very little life.
The film was however very controversial in its treatment of the subject: essentially the film squarely places the blame for the violence and bombings in Ireland of old, with the Catholic IRA (IRA rather like the ANC that Nelson Mandela was a member of!). It essentially decides for us that the Protestant para-militas (who shot and bombed just as many), the British army and the RUC (Royal Ulster Constabulary) were without blame in these troubles.
For this reason the film is somewhat of a disappointment in a country that is still trying to find peace, it plays the blame game when it should be at least recognizing that there was blame on all sides and the poor man in the street in the middle was the one that suffered most.
In some ways it does of course really say this at the films end, but there is a very skewered view of history being put forward throughout that leaves the viewer with no illusions where the directors sympathies lie.