Analysis of information sources in references of the Wikipedia article "Tetris (Game Boy video game)" in English language version.
2.5 million copies later, Tetris is Nintendo's top-selling title for the first few months of 1990.
"If I had known it would make big money, I wouldn't have given all the rights," he says, contemplating sales of 7.5 million copies in the United States, where Tetris is standard equipment for the Nintendo Game Boy hand-held unit.
