A bad interface doesn’t necessarily kill a game, but a bad interface with boring, simplistic, repetitive gameplay does. Consider combat. Pirates of the Caribbean is a role-playing game, and so of course you get to kill stuff. But in swordfights all you can do is attack and block. There aren’t any special maneuvers, and you can’t even move around much, and so combat is pretty much made up of sitting there with the block key pressed until all the bad guys attacking you swing at about the same time so you can retaliate. That’s boring, especially when creatures re-spawn every minute so you have to fight them over and over again, but at least it works. Later in the game blocking stops working (well, it starts reducing damage rather than eliminating it), and then combat becomes pretty random and causes all sorts of loading.