GFN works by linking your accounts on existing storefronts (Steam, Epic, GOG). Not all games from those libraries are supported (publishers have to opt in, not

GFN works by linking your accounts on existing storefronts (Steam, Epic, GOG). Not all games from those libraries are supported (publishers have to opt in, not out), but if you own a supported game already, you can stream it on GFN for free, or subscribe to a paid GFN tier for a better experience. Anecdotal numbers: I have a Steam library of 197 games and 44 of them are available on GFN.