Into the Breach, the second title from Subset Games (previously the excellent FTL), has today gained an official Linux build. It's been a long time coming, after originally releasing in 2018 but they always said they would do it and here it is. Fantastic!
"The remnants of human civilization are threatened by gigantic creatures breeding beneath the earth. You must control powerful mechs from the future to hold off this alien threat. Each attempt to save the world presents a new randomly generated challenge in this turn-based strategy game from the makers of FTL."
Check out the original release trailer below:
In their update announcement post on their official forum, they simply said "There is now a fully native Linux version of Into the Breach! If you already own the game on any storefront that normally supports Linux (Steam, Humble, or GOG), you should soon have the Linux version available for download.". More came with it though including new language support: French, Spanish, German, Italian, Russian, Polish, Brazilian-Portuguese, Simplified Chinese, and Japanese.
There's also now touch-screen support, updated game engine tech and some adjustments to modding support.
If you have Steam Play enabled, you may need to force the Steam Linux Runtime container (right click -> properties see here) to get it to download the Linux version, otherwise it defaults to Proton as it's on Valve's whitelist. Updated: this should no longer be needed.