hey maybe I could help, could you send me a screenshot of your project settings? It's really weird because I've never had issues deploying to Linux with Godot.
alright, I decided to try a few things.
first of all, I had an older build on me, so I exported it from that.
also, I figured the filesize may have been part of the issue, so I had it export from both versions without all the music which doesn't show up in the demo. try em both out and report back to me