I have this small issue here on my Kubuntu 15.10 system that it likes to switch the desktop resolution to 1360x786 instead of 1366x768 like the real screen resolution when switching between intel and nvidia optimus cards... I know complicated situation... and I don't even think it really switches as there is no streching, but KDE thinks the resolution is that.
Anyways... so when I tried to switch to fullscreen 1366x768 the music stopped the screen went black and I couldn't even properly alt-tab out of the game forcing me to log out via ctrl+alt+del.
So I guess choosing a resolution that is higher than you actual desktop resolution causes issues, and alt-tab also does not act as expected, as the KDE app switch side bar shows, but you can not actually switch as the black screen overlaid everything.