A slightly weak storyline is well hidden by the eye candy and special effects of this film. Acting I would rate as 7/10. Conceptually it is in the believable bracket…just. Not quite up there with Independence Day, but surpassed by the filming ect. The bonus 2nd disk is a great extra too. If you watch the movie first and then the 2nd disk on the making of the film, then future viewings of the movie is actually enhanced by the foreknowledge on this disk. But definitely watch the movie first, lol. All in all this movie will be a good addition to anyone's DVD library. Buy, and enjoy.