On the character select screen press X, Y, X, Y, X, Y then hold X. Press Left to decrease an attribute or Right to increase it.
Go to the custom cup screen and press L, R, L, R, X, Y. You will have 24 tracks available.
When you're in Suzulu 3, use this trick for an extra fast lap. As you pass the first large pond, turn left and follow the wall along. there will be a hole in the wall. Go through it to skip half the track.