The author of a book or screenplay is designing a linear experience. There is a fairly direct mapping between what they create and what the reader or viewer experiences. Game designers don’t have it so easy.
Quotes about books
A book or a movie tells a story, but it’s always telling more or less the same story. A game tells a different story each time you play it—even when these stories have lots in common. That’s why playing the same game again and again is much more common, more justifiable, more interesting, and more exhilarating than reading the same book again and again.