Nintendo has sold over 35 million copies of Brain Age. (All of these people also had to play the game on a console.)

Brain Age was based on the bestselling books, No wo Kitaeru Otona no Keisan Doriru and No wo Kitaeru Otona no Onyomi Doriru, which sold over 2 million copies and were authored by Professor Ryuta Kawashima of Tohoku University and the Kumon franchise of tutoring centers, originators of the famous Kumon Method of arithmetic education. (The english version is available here.)