A DSiWare version titled Brain Age Express: Math was released in North America on April 5, 2009 and in the PAL regions on June 19, 2009.
A DSiWare version titled Brain Age Express: Arts & Letters was released in North America on August 10, 2009.
The English and Korean versions of the first two Brain Age titles featured a Sudoku mode. The player can choose between two modes of play – with notification, or without. When played with notification, the game allows the player to miss only five times before the puzzle is automatically ended before completion. Each miss results in a 20-minute penalty which is added onto the player's time. Additionally, if the best time for a puzzle was achieved with notification, the game will make note of that next to the best time.
The majority of the puzzle takes place on the touch screen, which displays the entire Sudoku puzzle. The player must first tap on the square he wishes to fill in, and the touch screen will show a zoomed in image of that square while the other screen shows a zoomed out version of the puzzle. While zoomed in, you are able to move to another square next to it by using one of the arrows. To fill in a square, the player must handwrite the number using the stylus. Once the number is written and the player moves on from that square, it will be converted into a cleaner version of the number.
Brain Age also takes advantage of a strategy used in pen and paper Sudoku puzzles, in which the person marks which squares a number could possibly be by writing a miniature number. There are also four options at the player's disposal – Undo, Erase, Zoom Out, and Save & Quit. Undo allows the player to revert the latest change in the puzzle, Erase allows the player to erase everything in one square (alternatively, the player can circle just one number to erase it), Zoom Out is used to go back to a zoomed out view after the player has zoomed in on a square, and Save & Quit allows the player to do a quick save and quit the puzzle, which is erased once the player resumes.