Nah, this wouldn't be a specific save, though. It'd just be a flag that gets set if you beat the game even once.
When you hit new game, check for the flag. If it's set, you get to pick and choose 1 or 2 benefits or nothing at all if you want a fresh playthrough. Obviously, this wasn't what he was trying. It's just a compromise, if necessary. The "grade" example was just a feature form an existing series that sort of got this idea across. In essence, you can make it much simpler.