If you're looking for the recipe to a sure-fire little-theatre hit, here it is. Find a movie that has a certain cult following, the cultier the better, and then adapt it for the stage. If you can make it a musical, you'll be laughing, because the songs will help underscore the essential absurdity of the phenomenon.
Don't worry too much about slickness or professionalism - your audience will be largely composed of young people who seldom go to the theatre, and never to a musical, and have no standard against which to measure performance. What they seek is authenticity, fidelity to the spirit of the cult. Deliver that, and you're well on your way to establishing a hit