Waggle is a control scheme or game mechanic (usually from The Seventh Generation of Console Video Games) that is Cool, but Inefficient at best and a Scrappy Mechanic, unwanted upgrade, or Interface Screw at worst. It is thrown into a game to capitalize on a video game console's latest features — specifically, the interface and control schematics — but it worsens the gaming experience because it violates the game's mood, basic ergonomics, or playability.
Whether or not something is waggle is a source of debate among gaming fans, of course, like everything else. The color of the sky, for example.
No examples, please. This only defines the term.