The Wii Zapper is a plastic shell holding the Wii Remote and Nunchuk. It works with any game using Wii Remote pointer/IR aiming, not just shooters. Compatibility depends on control scheme support.
Note: Wii Remote Plus (built-in MotionPlus) required for Red Steel 2, Wii Sports Resort, Skyward Sword. Zapper works with Remote Plus. Check game manual for "Wii Zapper Compatible" logo.