And the M rating in Australia is like... pfftt. The M rating is defined as "Recommended for mature audiences." Recommended. This means that there's no enforcement for under 15s to go see the movie. It's like a serving suggestion on food packaging - we _suggest_ that you do it, but you don't have to if you don't wanna! And you don't even need adult supervision.

I think if the movie was truly intended for mature audiences then it would have an MA15+ rating (which is defined as "Not suitable for people under 15. Under 15s must be accompanied by a parent or guardian.")