Double Dragon II: The Revenge (Arcade)

Essentially a more refined version of the original Double Dragon arcade game, with numerous improvements such as sharper graphics and sounds, redesigned enemies and backgrounds, new moves, unique bosses instead of head swaps and the controversial decision of changing the original's punch and kick buttons in favor of directional attack buttons (oh yeah, and they killed off the girlfriend in this one).

Unused Graphics
The arcade version of Double Dragon II: The Revenge began development with the intention of being sold as an upgrade kit to the original. However, the scope of the project grew, forcing the developers to abandon this plan and release the sequel on a new board. With the exception of the Lee brothers and Machine Gun Willy, all of the returning characters from the first game were redesigned. Some leftover sprites have been left unchanged from the first game, while others have been redrawn for the sequel, but weren't put to use.