When you select Pattimo from the items menu, you are then on the song select menu, Enter the codes in before selecting your song. You can tell when you've entered the code correctly as a little coloured symbol appears at the bottom left hand side of the screen. Some of the codes can't be used at the same time as the others.
Code
Effect
L2 (x3) L1 (x2) right (x3), circle.
Makes all of the notes go into the middle bar. Makes the songs easier.
L2, right, L1, right, L2, L1.
Makes the notes disappear before hitting the top bar.
L2, L1, right, circle (x2).
Makes the notes move faster but appear further apart. The song is actually the same on this if you think about it.
right, L1 (x2), L2, L1, circle.
Notes in different places.
L2, L1, right, circle (x2), L2, L1, right, circle (x2).
Same as above only even faster and even further apart.