I know that game, lol. I used to think it was a joke when writers would say that a story took on a life of its own, its so true.
My Naruto fic Monster has truly become a monster. It was one of the few stories I knew the ending to but had to figure out a beginning, but I got soooo lost in the beginning and middle that it’s become this 400,000 word smut collection (mostly) It was intended to be a 20 chapter smut/horror story, laying heavy on the psychological horror aspect but I just had so many ideas for this and that, and it just turned into idk wtf. I’m slowly getting back to its roots, lol, but now that it’s gotten so huge, I’ve had no choice but to plan for two more parts after. I’ve put my foot down on going farther than a trilogy though, otherwise it’d never end and I’ve got other stories I need to work on.