The Onion AV Club has a fascinating regular feature called "The New Cult Canon," about films the cinema cognoscenti are into these days. They finally got around to covering that ultimate in cool cult flicks, Battle Royale.
And you can read it here.
The article neatly sums up all that is good and bad about Battle Royale, so I won't rehash it here. Suffice it to say, if you don't like violence, don't see this movie. I find it less disturbing than Suicide Circle, but others may have a lower threshold of nausea than I do. On the other hand, where else can you see Kuriyama Chiaki, Shibasaki Kou and Maeda Aki together in one all-singing, all-dancing, all-shooting movie?