At first, the aliens seem to want to talk and negotiate with the brightest minds of Earth, but when Marvin goes to the ship, he realizes that it is just a ruse and after escaping, he teams up with the government to stop the super-fast sound-based attacks that these aliens use.
On the first disc, there is not only commentary by Harryhausen, but also the original Black and White as well as a new Colorized version of the film. The colorization team seems to have done a fairly good job and it doesn't look all that bad; of course, the B&W version really gives that classic sci-fi feel.
On the other disc is an interview with Harryhausen about Earth vs. the Flying Saucers by Tim Burton, as well as a present day look at stop-motion animation and its effect on modern filming and special effects. Also of interest is a feature about the film's music and old 1950's ads for this film.
This is a must-buy for any fan of the old films or anything Harryhausen. If you loved his other works (Clash of the Titans, Jason and the Argonauts), then this is right up your alley.