This is spoilers, so don't read it if you don't want to hear what I thought about the movie, and a little bit about what happens. It's also mostly a copy-paste of something I posted in another forum. I just felt like sharing here too. 8)
The deplorable acts, and brutality of the movie can be directly related to current and past treatment of humans versus humans. I thought it was a novel idea to use that as a human vs alien concept. The movie was not was I was expecting, but that's not why I didn't like it. Taking the movie for what is was, not what I thought it was, I came up with this.
I think the movie had some good and unique ideas, and it was very well done, but I'm not sure I liked it. Beyond each event being entirely predictable, a few parts made me roll my eyes, stop caring, and disengage from the story. When Wikus hit Chris in the head and then tried to take control of the plan for himself (I'm trying to be vague for those who haven't seen it) I could have happily fallen through the giant gaping plot hole into my living room and far, far away from that terrible movie (if that was the ending). Luckily the movie didn't end there and slightly redeemed itself, but all in all there were more than a few scenes and glaring logical mistakes that just seemed beyond ridiculous. Those flaws pushed it from an analogous and almost-could've-been-wonderful movie about human nature; with a different story than your average storyline, to a decent movie I wouldn't recommend. It wasn't a bad movie exactly, and it was very well made, it's just the plot holes kept punching me in the face.
In more detail, and with extra spoilers...