UFO: Aftershock continues many years after the events of UFO: Aftermath, with alien scientists trying to change Earth into a giant living organism. As one of the survivors of the original invasion, you embark on a mission to find out what happened to Earth, the people left behind on the surface, and the new visitors. You must command elite ground troops and construct an intricate network of bases. Hone your attack strategy while discovering new technologies and items for development.