Usually I am not gung-ho to see a movie when I've already read the book. But in this case I'll make an exception!
If you haven't read the book, you may find this preview unintelligible. The book is an amalgam of different stories and genres, too. But in a good way. Once you get in the swing of it, it miraculously works.
For an explanation of how the movie came to be, scroll down on the same page and watch the Directors' Introduction video. That will help.
Beyond that, you'll just have to trust me: All will be made clear eventually and the temporary confusion is totally, totally worth it.
And if you're not up for the movie, read the book.