Quite kewl.
I have yet to see District 9, but from what I've seen of the trailers, it certainly seems worth watching.
It's not a bad drawing by any means, but I do have a few suggestions that you may (or may not) want to take up for future creations, such as using a sharper pencil for the outlines, and also perhaps trying to smudge your shaded areas where necessary using the tip of your finger (unless your finger's wet, then that's a bad idea). This would help disguise all the apparent pencil strokes.
Hope this review's helpful, and keep at it!