I've only heard good things about this movie and it was the only one from Clive Own's most popular movies I hadn't watched yet, and I must say... it completely caught me by surprise, especially when the story started picking up.
If there's a word to describe this movie (and it's hard to find a better movie to fit with that same word) it's breathtaking... this movie literally takes your breath away in some of its emotion-injecting scenes. The atmosphere is frightening real, it will immerse you into the movie and keep you on the edge of your seat in the final moments. A story with an incredibly real feeling of what could happen to humanity if it lost its innocence.
A disturbing movie indeed, but it's not that characteristic that makes this movie a masterpiece. What makes this movie a masterpiece is the themes in it, the ethic questions it evokes, the defiance of morals, the removing of liberty of choice and the using of aversion therapy to manipulate and create a "good" person in the eyes of society.
A dark and hideous vision of the future focusing the route violence, criminality and corruption are taking. Thought-provoking movie with a thrilling story about the young delinquent that goes through all this, with a performance worthy of praise.
The only truly horror movie I have seen (mind you, I have not seen many). It has all the elements a horror movie should have, excellently done and incredibly realistic: violent, frightening, disturbing, hopeless, no supernatural nonesense, human survival to the extreme.