The Atari XE System Lightgun. (XG-1) Was sold as a seperate package.   Originally this accessory and the "Bug Hunt" cartridge were packaged together with the Atari XE Game System.    To allow existing Atari 400/800, XL/XE computer owners the chance to also use this accessory and games designed for use with it, Atari sold it seperately.    The game also worked with the Atari 7800 PROsystem as well with games that were compatible.