When games is running a game and it has focus, double-clicking on a game file may show a "Resume?" dialog for the new game. When it happens, the game isn't paused as it should because double-clicking didn't make Games loose focus.

If you double-click on a file of the same game you still see it running behind the "Resume?" dialog.

If you double-click on a different one we can still hear the game running despite seeing the new one, and the previous game will still be running in the background and you can hear both games' musics.