Misleading plot description
While I really enjoyed the movie, I was a bit disappointed by the film not actually living up to the plot description. The description talks about Alice's "secret past" and "double life". But all she did was sleep with the neighbours and see her own ghost. While of course these things don't occur in the life of an average teenager, there's still not enough there for me to consider her actually having a double life. Just seemed a bit tame, that's all.
Oh, and with the Lake Mungo part, I totally thought she was burying an aborted fetus or something. That would have been pretty shocking, but the footage on her phone was still pretty awesome too.