Hi there!
It sounds like a screen resolution issue. It probably would be a good idea to go in and set the game to windowed. You can do that by opening settings.dat in a text editor from the RuntimeData folder in the game folder.
Sometimes you get strange interactions between Unity 3D and certain linux drivers in certain circumstances. It's a good chance that future drivers will not have this issue, but for the time being that workaround ought to work. Please do let me know if not.
Hope that helps!
Chris
