Yes, it works now, sorry for the confusion and thanks for the Linux support :-)
You have great graphics and I like the concept. I assume you are aware that this is basically a well-known chess variant: https://en.wikipedia.org/wiki/Losing_chess
It is great that you did not implement it as actual chess gameplay and add own aspects like the lava fields, it reminds me that you can do so many things on the premise of chess.
I also had a bug, once the opponent thought forever and the game did not continue.