Terri is just not your average movie. I can understand why some do not like this: you have to let yourself in on it. At first I was not immediately carried away, but as the story continues I slowly but surely got sucked in.
I would not call it a comedy at all, though some scenes made me smile. It touches on subjects which keep your mind occupied on that age (and later too, though different;-).
The movie shows lessons of life which some learn early in their life, others have to live through and never learn. It shows us we can make mistakes, we will, and we even have to if we want to "learn life".
I understood it got a more restricted rating than the average action movie. I can only think it has to do with the sexual subjects it contains, but I think it is done in such a way that you can only learn good things from it if you're young.
Cinematography does not do anything new, but it's a lot better and fitting than the shaky camera's of the 100 million dollar movies that came out lately.
So, lessons in life here!