RSS of notable FOSS games, feel free to comment more.

Broken:
themanaworld : https://updates.themanaworld.org/news.rss

opml file: 
<?xml version="1.0" encoding="UTF-8"?>
<opml version="1.1">
<head><title>subscriptions</title></head>
<body>
  <outline text="OSG">
    <outline type="rss" text="Alien Swarm: Reactive Drop" xmlUrl="https://reactivedrop.com/feed/" htmlUrl="https://reactivedrop.com/"/>
    <outline type="rss" text="Beyond All Reason | News Feed" xmlUrl="https://www.beyondallreason.info/news/rss.xml" htmlUrl="https://www.beyondallreason.info/news/rss.xml"/>
    <outline type="rss" text="Development Blog" xmlUrl="https://blog.supertuxkart.net/feeds/posts/default" htmlUrl="https://blog.supertuxkart.net/"/>
    <outline type="rss" text="Development Blog ★ Beyond All Reason RTS" xmlUrl="https://www.beyondallreason.info/microblogs/rss.xml" htmlUrl="https://www.beyondallreason.info/microblogs/rss.xml"/>
    <outline type="rss" text="FlightGear Flight Simulator" xmlUrl="https://www.flightgear.org/rss.xml" htmlUrl="https://www.flightgear.org/"/>
    <outline type="rss" text="Luanti Blog" xmlUrl="https://blog.luanti.org/feed.rss" htmlUrl="https://blog.minetest.net/"/>
    <outline type="rss" text="News – KeeperRL" xmlUrl="https://keeperrl.com/category/news/feed/" htmlUrl="https://keeperrl.com/"/>
    <outline type="rss" text="Release notes from pioneer" xmlUrl="https://github.com/pioneerspacesim/pioneer/releases.atom" htmlUrl="https://github.com/pioneerspacesim/pioneer/releases"/>
    <outline type="rss" text="Revolutionary Games Studio News" xmlUrl="https://www.revolutionarygamesstudio.com/feed/" htmlUrl="https://www.revolutionarygamesstudio.com/"/>
    <outline type="rss" text="Rigs of Rods Announcements" xmlUrl="https://forum.rigsofrods.org/forums/announcements.44/index.rss" htmlUrl="https://forum.rigsofrods.org/forums/announcements.44/index.rss"/>
    <outline type="rss" text="Unvanquished" xmlUrl="https://unvanquished.net/feed/" htmlUrl="https://unvanquished.net/"/>
    <outline type="rss" text="Veloren" xmlUrl="https://veloren.net/rss.xml" htmlUrl="https://veloren.net/rss.xml"/>
    <outline type="rss" text="Widelands news feed" xmlUrl="https://widelands.org/feeds/news/" htmlUrl="http://www.widelands.org/feeds/news/"/>
    <outline type="rss" text="Xonotic: The Free and Fast Arena Shooter" xmlUrl="https://xonotic.org/index.xml" htmlUrl="https://xonotic.org/index.xml"/>
  </outline>
</body>
</opml>