The story and the telling of that story in a video game are very liner they move in one direction never really changing, the way they make things interesting is by making the world no longer a linear world by adding side stories or time lapse where to do something in this time you would need to go back in time to get an Item. By changing the world to alter the story or putting a twist on a strong story can make something really powerful. This timeline shows how a story in a game can be changed and played with to add alternate endings, time lapses, plot twists, side stories as side quests but still shows it in a linear time flow. In the game Skyrim they do a very good show of side quest and alternate time lines or worlds they all flow into a different quest chain and branch off and some even flow into each other.