Probably the best place to try this is https://itch.io There are many projects there that are pay what you want. Usually developers ask for a few dollars but you can download for free if you don't want to pay. Honestly, I can't imagine the devs make too much from this, but it's worth giving a shot.
The other option would be to have a Patreon and actively support a game. I've seen some projects make a decent amount of money this way, but usually only for really weird games (like monster girl NSFW type stuff). There are people making a living this way, but it is rare.
