Operation C (known as Contra in Japan and Probotector in Europe) was the first handheld exclusive Contra game in the franchise. Released in February of 1991 in North America and January 8, 1991 in Japan, Operation C was developed by Konami and published by Konami, Ultra Games, and Mattel (in varying countries). Operation C was later released in Konami's Game Boy compilation cartridge titled Konami GB Collection Vol. 1, which was released in Japan and Europe.
The three versions of the game differed in a few ways. Naturally, Probotector replaced the human character with RD008, the robot from the two NES Probotector games. In the Japanese release, there was a stage select that made the first four stages accessible at any time. This stage select is only accessible by usage of the Konami code in the North American and European releases.
Operation C is a traditional run and gun shooter. Just as with the rest of the famously difficult Contra games, Operation C has numerous enemies, massive boss fights, and stages designed specifically to challenge the player. Operation C only has three power-ups (spread shot, fire gun, and homing, the third of which is introduced in this game), although the spread shot can be upgraded if it is picked up multiple times.