History of Double Dragon
Billy and Jimmy Lee, the protagonists of the series, fought their way in this beat-'em-up sidescrolled through a long and varied path. First was the coin-operated arcade game, released in 1987. Popular and loved for the action packed two-player co-op gameplay, it had a variety of moves and manoeuvres. It was challenging and competitive as it would force the players to fight each other if they actually manage to complete the game together. So no surprise that when the Nintendo version came out, it was an immediate hit. The only disappointment to the players was that there was no more co-op available, but that was returned next year in the release designed for the Sega Master System. The game was also released on many other systems, including Game Boy, Genesis and even Commodore 64.
Double Dragon was followed by two sequels (Double Dragon II: The Revenge and Double Dragon 3: The Rosetta Stone), both released for the arcade before the NES versions. These games had changes in the variety of available fighting moves and mildly in the general gameplay. The last game of the series to retain the beat-'em-up style was Super Double Dragon, released exclusively for Super NES in 1992. Later versions of the game, excluding the remakes, were made in a competitive fighting game style.
References to Billy and Jimmy Lee appear in many different games, directly or not. There is also a crossover game, titled Battletoads & Double Dragon, released for various platforms.
The most recent remake is Double Dragon Neon, released in 2012 as a reboot of the series.