And content is something of which you have to be mindful. Unlike with a novel, you are not writing this story alone. You can’t simply write “They rode on their horses to the castle where the dragon awaited!” unless you have horse models, the ability to have character models ride those horses, an area in which they are ridden, a visible castle towards which they must ride, a dragon model and a combat system that allows fighting such a large creature. If the team comes back and says, “letting the player see the castle from the outside will be really expensive… are you sure you want to do that? If so, we’ll need to cut some other levels.” At which point you change what you wrote to “They rode swiftly through the forest, and then there was a fade to black as they arrived in the courtyard. There the dragon awaited!”……“Hmm. Are you sure you want that dragon? Those horse models are really complex to do properly, especially if we need all the character models and their variations to have all the riding animations. Plus you said you wanted jousting. That’s a whole system. To do that and add a dragon, and dragon combat? I dunno.” Then you change what you wrote again: “They ran swiftly through the forest, and there was a fade to black as they arrived in the courtyard. There the dragon awaited!” “We have to cut some levels. That castle courtyard is really expensive, especially considering you only need it for the one scene. I mean, they go there and have the fight and leave after, right? Is it really that important?” Then you change what you wrote again: “They ran swiftly through the forest, and there was a fade to black as they arrived in the forest clearing. There the dragon awaited!” It’s a constant series of back-and-forth compromises, so even once you’ve written a good story and it’s passed muster with the rest of the team you’re still going to have to make changes on the fly. Big ones that will drive giant dump trucks through your plot, sometimes without leaving you enough time to go in and patch the holes.