So,  programmed the basics of the game I engine I would use to make my entry in Scratch, but there's one issue: I want the rewind to be smooth, but that would mean either have a list that updated every frame (which will probably be laggy and will have no limit.) or like 100 variables that are updated every frame (mega laggy), but can delete data that's unnecessary. I could also just mess around with save points, but that's sort of a last resort, since it's not exactly rewinding. So, any ideas?