Operation C

Operation C, released as Contra (コントラ) in Japan and Probotector in Europe and Oceania, is a 1991 run and gun game by Konami released for the Game Boy. It is the first portable installment in the series and features the same play mechanics as the NES versions of Contra and Super C.

Set after the events of Super Contra, the plot varies between versions of the game. In the original Japanese plot (the continuity that was later adapted in the English localization of Contra: Shattered Soldier), an unnamed hostile nation has taken a sample of an alien's cell with the purpose of developing new kinds of biological weapons through cloning technology. The Federation's chief gives a confidential order to veteran alien fighter, Bill Rizer, to prevent this plan.

In the North American localization, the unnamed hostile nation is replaced by the "Black Viper", an alien entity or organization related to Red Falcon from the previous games. Like Contra and Super C before it, the setting was also changed from the 27th century to present time, with the main character now identified as Scorpion (Lance).

The plot of the Probotector version, according to the manual and packaging, is almost a remake of the first Probotector for the NES, which in turn was an adaptation of the Japanese plot of the first Contra. However, the villain is identified as Black Viper in the Game Boy version of Probotector as well, rather than Red Falcon.

In the timeline presented in the Contra 4 manual and official website, the events of Operation C are depicted as a previous mission of "Mad Dog" and "Scorpion" (the new characters introduced in Contra 4) against the Black Viper organization. The Japanese localization of the game, Contra: Dual Spirits, makes no references to this revision.