For me, the Linux demo didn't work too well to begin with. I'm assuming due to having two monitors. It complained about software rendering and the mouse had graphical issues underneath.
Once I set into fullscreen and restarted it, then it worked great! Hopefully this can be fully sorted for release :)
Viewing post in Vengeful Heart Demo comments
Is that so? Thank you for telling me. I guess I shouldn't trust that renpy works on the platforms it says it works. I was sadly unable to test with linux anf mac, but I will find someone with those systems to try the full release when it comes out. I hope you enjoyed the game and thank you for the comment! :)