No worries, Thank you making this great game and supporting linux. Planning on buying the full game when it comes out :D
Edit: The updated version works! thx again!
I am experiencing the same issue on mint 19.2. The executable crashes and the jar does nothing when i try to run it (yes, i chose to try to run it with openjdk)
edit: also, the demo ran fine on mint 18.3, (no crashes or need to run the jar)
I started up the linux version and I got a black screen. The custom cursor and the music loaded ok but no picture. my machine is running linux mint xfce 18.3 and I am running the current version of the game