My guess is that District 9 will not make you feel happy, but it will certainly give you a lot to think about.  I found it very difficult to sit through.  I almost walked out in the middle because of all the violence.  As I have been walking the path toward being a happier person, I find violence more and more difficult to sit through.  So, honestly, if I knew what I know now, I would not have gone to see it.  If you are curious about getting the message but want to skip the violence, you might consider picking up the book (when it comes out).  I am glad I stuck it out though because it had such a poignant message.  The friend I went with wondered aloud why they had to use a sledghammer to drive that message  home.  I would like to offer my opinion on what that message was for one very important reason: though two people may look at exactly the same billboard, they still may receive different messages.  I can see how some people might walk away with a very different message.  So, without further adieu: I believe the message of District 9 was: we (human beings) can do better.  We can have more understanding for one another and act and re-act in a more kind, caring and HUMANE fashion.  The way humans treated the aliens was frighteningly similiar to how some human beings are treating other human beings right NOW.  We CAN do better.