A massive asteroid hurtles towards Earth, threatening to extinguish all life. Just in the nick of time, aliens arrive and mine the asteroid for its resources, causing it to break apart into smaller, manageable pieces. While the alien forces collect some of the debris, they abandon most of the smaller asteroids, which still pose a significant threat to Earth. It's up to you to destroy these remaining asteroids and ensure the survival of humanity. But be warned: the aliens aren't exactly cooperative...