Honest to go, you don't have to have seen the film to read the story. It's more like the difference between seeing the Harry Potter films when one hasn't read the books as opposed to going in already a fan--they both stand on their own, but in different ways.
I am glad that you liked the story, and wow, I'm glad that there's going to be a run on GBR (I don't know anyone who hasn't seen it at least once), because it is a funny black comedy.