Watched this last night and it wasn't what I was expecting even after reading several synopsis's and plots. Overall it is a very, very clever film which has left me and the wife continually asking each other "why did this happen and why did that happen and who did this........................."
There are several questions I wanted clearing and so spent a bit of time this morning trying to find answers. Most can be found here
http://boards.ign.com/district_9/b24646/183950353/p1/ WARNING CONTAINS SPOILERS!!!!!Anyway, marks out of 10........ probably 8. Only after my questions were answered though. The link above explains all.