Only two of the six sections of the book are sci-fi, the others cover quite a few different styles and genres. The book is unique, but I only found it interesting as a self-consciously clever stylistic and conceptual exercise. The actual stories and characters themselves were pretty forgettable and perfunctory, a real slog to get through at times.
A good movie could be made of it though. I found the most interesting things about the book were the 'bigger picture' aspects, and condensing the whole thing to screenplay length could play to the book's strengths, namely the huge amount of variety in the different stories and the clever russian doll structure.