'Tetris' creator says the iconic game's success was largely down to the Game Boy.
Alexey Pajitnov, the designer behind the tile-matching puzzle video game - which launched in 1984 - has admitted that the classic handheld console proved to be the best way to play the title because it was all one colour.
He told TODAY: "'Tetris' was a good fit because it was a fun game that appealed to everyone, no matter your age, gender or culture.
"It wasn't a game just aimed at kids, for instance, or limited because of the language you speak.
"Also, seeing the colors in 'Tetris' were not needed to play the game, which was a benefit given that the Game Boy was one colour."
He added that 'Tetris' was appealing because it's "visually attractive because of its use of geometry, and (it was) intellectually challenging. And it doesn't hurt that the game has a peaceful, non-distractive style."