I loved this movie and found it very moving and thought-provoking. The special effects were amazing; the action riveting. Would recommend it to anyone over 12-13 years old. You don't have to be a fan of sci-fi to enjoy it.
Having said all that, the story itself is fairly formulaic. Without the fabulous graphics, it wouldn't be all that great. But, believe me, you won't care; even if you step back and see the plot line for what it is, you'll still be riveted by the whole experience.