Gamasutra - Is It Time To Start Pre-Selling Games?
The next element that makes pre-sales possible is the predictability of production. We aren’t speaking of whether or not a film achieves the mysterious qualitative “X” that means it will become great art. Rather, we’re speaking of whether or not there are standardized processes and suppliers that can be put together with a screenplay and, with a fair degree of predictability, lead to a reasonably high-quality film. If the film missed its aesthetic mark, at least you have a “well-made” piece of cinema that can be sold -– at least you have something.

Gamasutra - The Uneasy Merging of Narrative and Gameplay.
Strictly speaking, two forms of media that video games are best (and uniquely) suited to express are visual narratives (like film), and gameplay (which specifically is a subset of human-computer interaction). Now most people agree that film is better-suited to expressing straight narrative than a game is. But gameplay is a unique quality of video games, and video games are also quite well-suited to expressing narrative, technically speaking -- they have most all the capabilities that film does.