I don't know much about Linux but I do know Unity is very specific on how they run WebGL games, I think the only way to run the game is play it in the browser on the itch.io page. I will try to find a way to fix this but I don't think I know how. Also I didn't even realize it was downloadable, it wasn't supposed to be because it doesn't work. But thanks for letting me know, I will try my best to fix it.