I thought it was a pretty good movie. I admit the characters were flat and the storyline was like Braveheart meets Greenpeace, but it had great action scenes, beautiful flora and fauna, and probably one of the better messages to come out of a movie lately: That human beings are horrible things. That, and we need to protect the planet so that we don't get fucked over like Earth in that movie was.
But for some reason, the instant I stepped into the theatre, I knew there would be freaky, Mass Effect-like, blue alien sex. And I was right.