Tetris: five cheesy ads to celebrate 25 years

It's been 25 years since Alexey Pajitnov, then a 29-year-old artificial intelligence researcher, came up with Tetris while working at the Soviet Academy of Sciences in Moscow. "A quarter of a century later," the Guardian reports, "it has a legitimate claim to being the videogame that has truly conquered the world. In all its forms, Tetris has sold more than 70 million copies around the globe; it has spawned architecture, art and music; it has earned multiple Guinness World Records; and is regularly voted one of the top games of all time."