Dune: Adventures in the Imperium does a version of this. Extra successes on a challenge give the players Momentum points which they can use to generally make things better for them. But the GM has Threat points which make things harder for the players. Points can also be used to buy off bad outcomes or improve good ones.
But the most fun bit is that the GM can cash in a bunch of Threat to introduce a rival to the players into a scene. So their nemesis can drop in on the party where they’re trying to gather allies to confront the nemesis.
It wasn’t quite as simple as that. From what I remember, the rights to Watchmen were supposed to revert to him after the book went out of print. But DC just kept the book in print forever, denying Moore any say in what was done. Keep in mind this wasn’t normally done at the time, it was a pretty underhanded move they pulled, especially after Moore did so much good work for them (Swamp Thing, Green Lantern, the Phantom Stranger, etc.).
They screwed him, make no doubt.