I love this game, but it turned out to be way more than my PC can handle.
I got GFN a month or so ago, and it let’s me play games like Cities Skylines just fine (it will slow my PC to a crawl if I try to play it natively.)
Steam and Nvidia handle the technical end. When GFN was in beta, you could play almost any game in your Steam library and I guess that was just before your game was released. When GFN went gold, lots of game publishers with games on steam said, nope (no one has a really factual answer why.)
Nvidia is desperate for more games. Just pop them a letter/email. What have you got to lose?