Starsector (formerly "Starfarer") is a game that I've followed for quite a few years now, one I personally purchased many years ago and the latest release is a big one.
One I spotted recently, Behold Studios (Galaxy of Pen & Paper, Knights of Pen and Paper) are working on a new game called Out of Space and it sounds interesting enough.
After waiting since last summer, Behold Studios have now managed to add official Linux support to Galaxy of Pen & Paper along with the +1 edition free update.
If there's one thing I didn't like about Graveyard Keeper is all the constant manual labour. Well, not so much now as you will be able to resurrect bodies to do your bidding.
Nimbatus - The Space Drone Constructor is an excellent Early Access game where you snap blocks together to make some truly ridiculous creations. Stray Fawn Studio have now outlined their future plans and it sounds fun.
GDevelop is an open source cross-platform event-driven game engine that's quite promising. It's currently closing in on a new major release and it's also now on itch.io.
God is a Cube: Programming Robot Cubes is a programming puzzle game currently in Early Access with Linux support, it's actually quite good and we have a few copies to give away.
Hypergate from developer Geoff Nagy seems like a pretty good space combat sim that will release with Linux support in December. It has a new trailer to show off.
If you fancy trying to pilot a ship in between hundreds of tiny little asteroids now is your chance, Rings of Saturn might be delayed until next year but the demo seems to work well.
Good news for those who love their building games, as settlement building game The Colonists looks fantastic and the developer has confirmed their plans for Linux support.