The game "Tetris," which became a global phenomenon, was actually created by a Russian computer scientist named Alexey Pajitnov in 1984. Pajitnov developed the game while working at the Computer Center of the Russian Academy of Sciences in Moscow. It was initially intended as a test for computer graphics, and its addictive gameplay quickly made it a hit among his colleagues. The game spread to the West in the late 1980s, eventually becoming one of the most influential and best-selling video games of all time. Interestingly, Pajitnov didn’t see substantial financial rewards from "Tetris" until years later, due to the complex licensing and distribution deals. 

The "Konami Code," one of the most famous cheat codes in video game history, first appeared in the 1986 game "Gradius" for the NES. This code, which is typically entered as Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start, was initially included by developer Kazuhisa Hashimoto as a way to help himself test the game’s difficulty levels. It later became a well-known cheat code for unlocking various in-game advantages and secrets across many Konami games, including "Contra," where it famously provided 30 extra lives.