Just the theme alone of this movie is enough to warrant it an R rating. Aliens and predators: both scary as hell. There is no way the MPAA will give it a PG-13. Look at signs. No blood, gore, violence, or language (if i can remember) of any kind, but it was the scare factor of that movie. It still scares the shit out of me. It got a PG-13 just because it was scary. Now if they add the traditional violence of the Alien and Predator sagas, you have an R rated film. Not to mention the language and innuendo. I simply cant imagine the MPAA allowing any kids to see this movie. Remember in the end it isn't FOX that rates this movie, its the MPAA.