I really shouldn't start out a film conversation with -- best soundtrack of the year, but oh yes it is (even better than Richard Linklater's Boyhood? Yes.), and it sets the pace for the humor that ribbons throughout the entire movie. Half the time the songs are the humor, since they add to the ongoing inside joke on us silly, quaint, emotional, humans. We love our nostalgia and having aliens misunderstand it makes for even more merry making.
Yes, yes you are going to compare the film to Star Wars and Raiders of the Lost Ark, but anything this over the top will be with tongue planted in cheek and will give you a comedic historical reference, that is well, fun.