Looks like version 0.80.2 doesn't hide the system cursor and uses that for 'default' interactions. It does mean you see both the "mouth" cursor and the system cursor when using "mouth" interactions, but thats not much of a problem. It also means that the game is now playable on ubuntu once more. There is one hurdle however. For me the game started in a very high resolution and in windowed mode by default. Meaning most of the window fell off the screen and most of the UI was not usable. This was fix-able by using the 'super button' (windows symbol on windows compatible keyboards). If you hold this button and drag the cursor around, you can move the window to whatever position so you can access the "Options" button. There I could change the resolution. There were a couple of options including my native screen size. This was still to large however, as there is still the window title bar in windowed mode. Setting the resolution to my screen native resolution and setting the game to fullscreen mode finally allowed me to see everything.