Konami Code

https://en.m.wikipedia.org/wiki/Konami_Code

The Konami Code (Japanese: コナミコマンド, Konami komando, "Konami command") is a cheat code that appears in many Konami video games,^[1] and some non-Konami games.^[2] In the original code, the player can press the following sequence of buttons on the game controller to enable a cheat or other effects:

↑↑↓↓←→←→BA

The code has also found a place in popular culture as a reference to the third generation of video game consoles,^[3] and is present as an Easter egg in a number of websites.^{[4][5][6][7][8]}