List of Konami games using the code Gradius series In many titles, the player must press Start after entering the code in order to start a game, or press Select to switch to two-player mode and then start the game, leading to the confusion. A common misconception is that the code ends with Start or Select Start. Despite the differences, though, these codes are still often referred to in general discussion as "Konami Code", "Conami Kode", or, less commonly, "Pseudo-Konami Code". These deviations may occur for purely operational reasons (e.g., if the code must be entered while the game is paused, the code might be altered to avoid resuming), to keep powerful upgrades better concealed while still referencing Konami, or through a programming error.
The Konami Code was created by Kazuhisa Hashimoto who was developing the home port of the 1985 arcade game Gradius for the NES. The code was first used in the 1986 release of Gradius, a scrolling shooter for the NES and was popularized among North American players in the NES version of Contra, for which it was also dubbed both the "Contra Code" and "30 Lives Code", because of its near necessity in-game.