Generally I concur with the other review - although I would like to clarify one thing - Mick Lally and Cyril Cusack (father of the extraordinarily talented Cusack clan from Irish and British stage and screen) were in Glenroe together. Cyril died long before Bally-K was filmed.
Personally, I've never rated Niall Tobin's acting overmuch - however Donal McCann, who was sadly taken from us too soon, put in a sterling performance. Many of the actors would have been quite local to where the film was shot with the principal "big name" actors recruited from the national circuit. Some are still going - most notably in the Irish-language soap, Ros na Rún
It's not an easy film to watch, particularly the scene with the dog. It was usually turned off or switched over at that point. But Bob Quinn is a good director who produced intense thought-provoking films.