Then you'll want to fix that fullscreen issue :P Standard for unixes is to go fullscreen on the monitor the application window is already on, not force it onto the primary one (this appears to be a common screwup with unity, since that would happen automatically with X11/OpenGL).
My pleasure, though. The rest of it seems to be well coded and nice and stable; a fun little game. It reminds me of Battalion for some reason :)