“Both of the main River City Girls games from WayForward have featured cameos from the Double Dragon series. River City Girls 2 even made Marian an unlockable character. Still, fans have always longed for more Double Dragon content in RCG 2. Now they finally get their wish thanks to the “Double Dragon DLC.” The paid DLC adds Billy and Jimmy Lee as playable characters, essentially transforming RCG 2 into a weird, awesome Double Dragon game,” says Co-Optimus.
Source: N4G PC River City Girls 2: Double Dragon DLC Review [Co-Optimus]