Double Dragon (NES)

Double Dragon (ダブルドラゴン) is a 1987 arcade beat 'em up developed by Technos Japan and distributed in North America and Europe by Taito Corporation. The game is a spiritual and technological successor to Technos' earlier beat 'em up, Nekketsu Kōha Kunio-kun (released outside of Japan by Taito as Renegade), but introduced several additions such as two-player cooperative gameplay and the ability to arm oneself with an enemy's weapon after disarming them. Double Dragon is considered to be one of the first successful examples of the genre, resulting in the creation of two arcade sequels and several spinoffs, as well as inspiring other companies in creating their own beat 'em ups.

Double Dragon was ported to the NES by Technos Japan in 1988. The game was published in North America by Tradewest (who was given the license to produce other home versions of the game as well) and by Nintendo in Europe. The NES version of Double Dragon was released for the Wii Virtual Console service in Europe and North America on 2008. The most notable difference the NES version has from the arcade game is the omission of the arcade's two players cooperative game mode. Instead, the two-players mode in the main game ("Mode A") is done by alternating, although both players take control of Billy. In this version, Jimmy Lee (the Player 2 character in the arcade version) serves as the main antagonist. After defeating Willy, the original final boss from the arcade game, Jimmy will appear before the player for the true final battle.

Due to technical limitations of the NES that were not worked around, the game can only generate two enemies on-screen to confront the player and both enemies are the same character. Additionally, weapons cannot be brought to the next fight if the original enemy carrying it is defeated. A level-up system was also implemented. The player begins the game with only the basic punches and kicks available to their character, gaining the more powerful ones after acquiring the experience points needed to use them. The player has a total of seven skill levels that they can achieve throughout the game. The level designs are very different, with some stages featuring new areas (notably the cavern section in Mission 3) that features greater emphasis on jumping over platforms or evading traps. All of the enemies from the arcade game also appear, with the exception of Jeff and the mohawk version of Abobo, the two head swap characters from the arcade game. A new enemy named Chin Taimei appears in this version as the second stage boss.

The NES version features a bonus game mode (dubbed "Mode B") where the player can choose between Billy or one of five enemy characters from the main game and compete against a double of their character controlled by the computer or a second player in a one-on-one match. Matches against the computer are handicapped in favor of the computer-controlled character, while certain characters will get a chance to wield a weapon in the 2-Players matches. Double Dragon was only the second game that Technos developed for the NES, and the two-player mode was reputedly omitted because of the programmers' inexperience with the hardware. This also accounts for the game's large number of bugs and glitches.