Fun Fact: The NES version of the game features a happy ending, where the woman players are trying to save is alive. That's not the case in the original, arcade version.
Double Dragon II: The Revenge was a side-scrolling beat-em-up. It was also an arcade port but had significant improvements over the original version including new levels, new fighting moves, and featured the addition of animated cut scenes.
Double Dragon II was a particularly fun co-op experience if you turned on the option that allowed players to hurt each other. The default mode made it impossible for player attacks to damage other players by accident. Turning this mode on made for some hilarious backstabbing.