I've got the same problem on Ubuntu 18.04. What I'm seeing is clearly an in-game mouse cursor, so it's not as if it's impossible to interact with the game: it appears to recognise that the mouse is being moved, at least. It's just that (as TitiMoby says) nothing happens when I click any of the options.
I also tried plugging in a gamepad just in case that was an option, but no luck there either. Please do let me know if you ever sort this. It looks like a neat game, and I might try seeing if I can get the Windows version to run in WINE in the meantime.