Contra – The Konami Code
These days, game studios know that it’s never wise to make a game so hard that players won’t stand a chance of finishing it. That never occurred to Konami, as “Contra” remains one of the most unbeatable games ever created. To help, the programmers input a secret button combination—Up, Up, Down, Down, Left, Right, Left, Right, B, A (Start)—that granted players 30 extra lives. The code was first used in Gradius, but “Contra” made the Konami Code famous, making its way into nearly every one of the publisher’s games, and is still adopted by game developers or referenced in pop culture to this day.