https://itch.io/games/code-gpl3
...and replace gpl3 with: gpl2, lgpl3, lgpl2, mit, bsd2, bsd3, apache2, artistic, epl, mpl, unlicense, zlib.
...and replace gpl3 with: gpl2, lgpl3, lgpl2, mit, bsd2, bsd3, apache2, artistic, epl, mpl, unlicense, zlib.
Itch has this filter: https://itch.io/games/tag-open-source
As a bonus here are some random non abandoned lists I found with quick search:
https://en.wikipedia.org/wiki/List_of_open-source_video_game...
I don't think it's a proper filter, looks like just a tag that needs to be manually applied to the game somewhere. I can tell it's not showing some FLOSS games with correctly filled out license metadata.