I am now thinking if you can pull off an adventure game where some puzzles require editing the save file. It would be pretty tricky to make it understandable to most people. Now that I think about it, I wouldn't put it past Deltarune to eventually have an easter egg that can only be reached from a save state, which is impossible to achieve through normal gameplay. I know it doesn't have one right now, because all the scripts have been examined in depth and nothing like that was found.