The medium matters. And context does too. This is a videogame. I have to play through your content. You are writing what I assume is a book or comic.
I’m Sos case, those first 5 hours are useless. Does it help to know where the main protagonists came from? Sure. It adds to the story. But if I have to play through that and none of that ends up being relevant to the story, then it was filler content.
I saw a comment where they compared this game to chrono trigger, saying how in 5 hours toy had traveled back and forth through time twice, rescued a princess, got in a trial for kidnapping and added 5 characters to your party.