Java11 is minimum Java version. On Linux it is possible to install only java-headless which means it does not have GUI support and that does not work. Have you tried running it with command "java -jar Open-Realm-of-Stars-0.27.0.jar" from command prompt or terminal? It should show more info on Java exception occurred. Do you see any stack traces?
I'm using Windows 10... it seems that despite trying to get the newest version of Java I ended up with version 8... maybe Windows' fault due to its version? I don't know. I'll try and find time to troubleshoot (more uninstalls probably) but it looks like the problem is squarely at my end (the error message given said it could only run packages up to version 52 but this game was packaged with version 55).
Apologies for the trouble.