Nah, the issue is that JavaFX isn't included in OpenJDK. This causes issues with both Linux and macOS.
Oddly enough, I've found that the most consistent way around this is to run it in an IDE (development environment) as that'll pull down all of the dependencies for you. I'm admittedly not a Java expert, but it really seems like packaging a JAR for multiplatform releases is a far bigger pain in the ass than it should be.
I'll see if I can find a way to make the process somewhat straightforward. No promises, though.
Ok, thanks for the advice, but there is a bit more which I found out after dancing around the computer with every possible known occult fetish in existence.
For people who struggle to launch the game on mac, here is a quick guide:
1. Download JDK FX build, the latest the better (you can find them on ZULU)
2. Install it, DONT FORGET TO SWITCH YOUR BASE JDK IN TERMINAL, otherwise it may not work.
3. Restart your pc, sometimes it takes more than on restart for the pc to finally register that there is indeed a new JDK on the system.
the game now should work. God, I feel like a mechanicus techpriest who prays that machine spirit wont personally fuck them over.