secret 1-Pick your ball color: After you pick your mii a warning screen appears. Press and hold up,down, left or right on the D-pad. While still pressing the D-pad hold A until the game begins. The direction you press will ditermine your color.
Up-blue
Down-green
Left-red
Right-gold
Secret 2-How to play on a blue tennis court: After you pick your mii a warning screen will appear press & hold 2 and then you press A.