Though Ive heard MANY arguments about how "its been done before" and "how it doesn't explain itself enough" all i hear is "i don't know how to sit my bottom down and enjoy a good fun movie that draws me in and takes me for a ride." The story gives you enough to make you feel for the world and its creatures but doesn't bog you down too much with the science of the sci-fi genre. It is made as a movie that can be enjoyed by a wide breath of people, and though some may again argue that by doing so it loses some of its potency... but again i say they are missing the point. I've seen this with friends and family, and it all ends the same way. With everyone leaving the theater saying "how much fun that was"