Its nothing that mysterious, its a very well told story with terrific characters that has all the elements imaginative young boys like--chases, explosions, awesome special effects, aliens, shoot-outs, swordfights and every possible matinee staple from pirate adventures to cowboy films. Throw in the always-popular story of the underdog triumphing, of the little guy "going the distance", a nobody becoming a somebody, something everyone years to be but most importantly young kids, and you have a formula for a classic. There really isn't any other movie that has combined these elements in quite a way since, LOTR being the closests comparison perhaps but the super-melodramatic gravitas and overlylong running time of those films prevent it from being as accessible for casual viewing as the more straightforward Star Wars films.