Thanks for playing. I don't have access to Linux at the moment so unfortunately I'm not able to test it. This is probably a Unity platform specific bug. I hope to release a Linux standalone version in the future so this will not be a problem.
By the way I figured out the workaround for the unity games that have this problem, you can set WINE to emulate a virtual desktop, which fixes some focus issues or something. I can pretend I'm playing windowed if I set the game to fullscreen since then it just takes up the window for the virtual desktop.
Found this out while trying to pirate rimworld, then I pulled an all-nighter+ and forgot about my stream slot