I'd like the control mechanism to work similarly on all platforms, because that way adding a new platform front end is O(1) effort rather than O(number of games), and adding a new game back end is O(1) rather than O(number of platforms). Since my ultimate aim is to end up with loads of games all running on loads of platforms, this will eventually become a serious concern :-)

Anyway, I think I've improved matters now without having to resort to mouse hovering.