There’s an adage in games writing: No one cares about your stupid story.
This doesn’t mean that games shouldn’t have stories. It feels better to run through a space station shooting aliens in order to save the world than it does to run through a context-less maze shooting nondescript enemies in order to win the game. What it means is that designers and writers shouldn’t self-indulgently splurge their stories into the game and expect players to sit through them when they would rather be playing. Capture their attention, make seeing the story an engaging experience, and you can get them to swallow quite complex stories and even sit through long non-interactive sequences. But you’ve got to remember that they start off from a position of not caring about your stupid story, and you have to convince them to care.
I think the same thing applies to writing prose fiction, to a greater or lesser extent. Lesser because a reader has bought your book for the story so they’re at least in a mood that’s sympathetic towards caring about it–but greater because the story is all there is. I’ve enjoyed games despite poorly-told stories, but if someone doesn’t enjoy the story of your book then they don’t enjoy your book, and they won’t be buying your next one.
When I’m writing prose, I try to look at each section I write and ask myself, why should the reader care? In a hypothetical game adaptation of the book, is this section something players would be watching or playing with rapt engagement, or is this something they’d want to skip to get to the next good bit?
Beginnings, in particular, need to grab the reader’s attention. I hate long opening cutscenes in games, and I hate long boring prologues in books. The same passage might grab my attention half way through the game or book, but at the very beginning I don’t yet care. But that’s not a license to start with an in medias res action scene and then jump back to your dry infodump assuming the ‘caring debt’ the reader has built up will carry them through the next passage. If you need to convey some information, do so in the most interesting way you can. And if, after a long dispassionate look at a particular passage or scene or idea, you don’t think the reader will care about it–cut it out.