To get a platinum medal in Charge!, (Cow Racing) just knock over ALL of the scarecrows, and it will say "Perfect!" at the end. My record is 328 or something... Try to beat it!

To get a higher score on the Mii Spoting game, have someone stand right next to the tv and help point out where the certain Mii you're looking for is

If you press A + B at the same time while the screen is showing start you'll be able to change Paddles from circle to normal