Thanks for the update and the offer. We had a great time with the jam! Pretty bummed to see how fickle it is on Linux (who knows what's going on with MacOS 😓). I just now got in contact with someone running Ubuntu on bare metal, and the game is working great for them, so that boosted my spirits a little bit.
I have essentially no experience with Linux desktop, just a bit of server side stuff. The game is targeting GLES 3, so maybe your box doesn't have support for that? That could explain why its not hitting the hardware, though its kind of strange you weren't seeing much CPU usage either. Maybe there is some driver issue? Regardless, it seems to work on Ubuntu as long as its marked as executable in the file properties, so there is at least some kind of Ubuntu support.
Thanks again for the back and forth. I appreciate the effort.