Operation C is a Game Boy sequel to the popular NES titles Contra and Super C and is, essentially, a side-scrolling shooter. You play a Rambo-esque character that goes around shooting everything in sight, collecting weapon upgrades and bonuses.

The game introduces the character of Black Viper to the series' oft-jumbled continuity. Black Viper would later return in the Nintendo DS title, Contra 4, as the primary villain.

The game features only five levels, two of which are played from an overhead perspective similar to Super C. Operation C is also notable in featuring the upgradable Spread Gun (from three to five shots) and introducing the Hunter Gun.

There is also the occasional platform element such as jumping puzzles, moving platforms etc., and the mandatory end-level boss.