I've already made a thread on the official forums: https://forums.inxile-entertainment.com/viewtopic.php?f=47&t=17194

This is getting really tiresome with kickstarter projects.

If you have the game files in a path with a space (" "), try moving them to a path without a space.

The game NEEDS SDL_AUDIODRIVER=pulse!!! If you set that it will start. Albeit without sound. If you want sound as well you need to have pulseaudio installed. Unity3d is shit on a stick.