A game that is a cozy, charming farm simulator, is open source (GPL V3 if I can have my way), is in a source forge that would put it in a more mature development state, and is available pre-compiled outside of steam?

I don’t see plenty or any in there that match this

I’m going to be honest, you sound like a zealot. Uncompromising about your ideals about gaming, and any that don’t conform to it exactly are “not impressive” in your own words. I’m not opposed to libregaming, and everything that’s listed on that page you linked sounds great on paper, but in reality, doesn’t always work out the greatest. This isn’t the '90s where you can go and create an open source game for everyone to enjoy and everything works out fine in the end. This is the age of artificial intelligence, which is already known to be scraping and stealing large amounts of copyrighted works from the web and using them in ways that are unknown. This unknown is actually quite damaging to the gaming industry as a whole, and even threatens the idea of Libregaming. worst case scenario, AI models get their hands on the source code for someone’s new game, and now, someone who has never programmed a day in their life can use an AI model to create the exact same game with no credit given to the original creator. That’s not that far-fetched in the current day and age. Perhaps that’s the reason why Stardew and other games don’t want to be open source? So people can’t just steal their hard work after years and years, and then go churn another one out.

There are dozens of other reasons as well why it doesn’t work, but this isn’t really the time or place to explain it. I would recommend though that you remain a little bit more open to games that are closed source, because there’s a whole team working on mistria, it’s not just a solo developer. It’s their right to keep their game closed source as an indie developer. That’s totally their choice

Plenty? Okay, name me one open source farming games that have feature parity to this game/Harvest Moon/Stardew Valley.