The Konami code is one of the most famous video game cheats of all time, but how did it come about? According to a translated chat between Konami's Kazuhisa Hashimoto and Shigeharu Umezaki, it all started with the NES port of Gradius.
Hashimoto, the code's creator, explains:
I had one guy under me, and he played through the coin-op version. That one’s really tough. I hadn’t played that much and obviously couldn’t beat it myself, so I put in the Konami Code. laughing