If it is supposed to be a Haneke film, it does have a couple of pitfalls. It is not Haneke's best, perhaps because maybe he felt the pressure to top Der Siebente Kontinent. As someone said previously, it is rather heavyweight towards the end.
As a film without regarding who directed it, it is very good. It provides you with a raw documentary vision of a boy and his voyeuristic trend towards violence. It is rather simple yet, an amazing idea. Benny could be the boy living next door and, in fact, he is. He is not frightning on a "I know what you did last Summer" fashion. He is _truly_ frightning because he is a normal kid. And I do know a few like him. The ones I know never actually murdered anyone but, perhaps they simply didn't do it because they are afraid. Benny hasn't come to terms with that moral feeling yet and perhaps he never will.
On a metaphorical sense, it is the best portrait (along with Der Siebente Kontinent) of present day Austria, at least the Austria I see at some September rainy Vienna weekends...