>>11958392
Tiny Toon Adventures: Buster Busts Loose for the SNES has an implementation of this that I liked. Every level has additional parts added as you increase the difficulty from Children, Normal, and Challenge. So if you start out on the easiest difficulty, it's easy and short. And as you move up the game gets harder (not that hard) and longer. The endings are probably different too, but I don't remember for sure.
I haven't played the game since I was a kid, but I remember really enjoying the game. I need to go back and revisit it.