Each player during their turn selects two boxes. If the contents of the two boxes matches, then they are awarded points and they get to choose again. If they guess wrong, then the next player gets to play. When all pairs have been selected the game ends.
If a window has a button and no editable text field, then the button may be selected by pressing the key for the first letter in the name of a button.
The About Concentration window can be closed by either clicking on the window or pressing any typeable key on the keyboard. The timeout only works when Concentration ][ first starts.
