Early in the movie, Henk talks about how when he sleeps he can still see the Tetris pieces in his dreams. This is actually a real phenomenon called the Tetris Effect. The term was coined by journalist Jeffrey Goldsmith in 1994 to describe when something that one focuses on for extended periods of time starts appearing in their thoughts, perceptions, and dreams.
Being a non-gamer, then Nintendo President Hiroshi Yamauchi would give the game to his superstar programmer Shigeru Miyamoto, the creator of their most popular franchises Super Mario and The Legend of Zelda, to see what he thought. Several days later, Miyamoto confirmed to Yamauchi that it was a great game and when Yamauchi asked why, Miyamoto responded "Because even your secretaries and accountants are playing it!"
Former Nintendo President Hiroshi Yamauchi was known to be a serious, stern businessman, but he had a very friendly, cordial relationship with Henk Rogers. This came about from their mutual interest in the board game Go. Rogers would often visit Yamauchi and the two would play together while discussing potential new games for the Famicom (Nintendo Entertainment System).
Atari produced about 300,000 copies of Tetris for the Nintendo Entertainment System under their Tengen label. Eventually, they would be forced to stop producing these cartridges once it was determined they did not have the rights to the game. The game is now considered a collector's item and is one of the rarest, most valuable games for the Atari Corporation.
Tetris (1984) was the best-selling video game of all time from 1993 until 2020, when it was surpassed by Minecraft (2009). However, it should be noted that 17 years includes all ports of the game, which vary technically from one version to the next. The now-defunct mobile version developed by EA had alone sold over 100 million copies, making it the third best-selling game after Minecraft and Grand Theft Auto V (2013). The Tetris franchise as a whole has sold nearly 500 million copies, making it the second best-selling game franchise after Mario.