Does the Linux version run for anyone (except the developer)? I've tested it on three different machines with three different distributions (Slackware64 current with proprietary NVIDIA driver, openSUSE Leap 15.0 with radeon driver and Ubuntu 18.04 with open source nvidia driver), and on all of them there is no sound and the game is just freezing after a few seconds in the game...
Would you mind sending us a log file to check what's going wrong for you? You should find one in ~/.config/unity3d/Semaeopus/OffGrid/player.log. Just send it to support(at)semaeopus.com and I'll take a look. The build's been tested on Ubuntu 18.04 with proprietary nVidia drivers, at the moment I really wouldn't expect the open-source nVidia drivers to handle it. And as far as I'm aware, others have ran it in Ubuntu and Arch at least without any problems.