This allows you to set the speed in the Options to 10.
On the Start Screen, hold Y and press L, L, R, Down, Left, R.
You should then hear a beep.
Now you can play super fast.
Go to the Select Screen and enter these codes.
Thunder = Hold Up-Right and press Y, B, X, B, B, X, A
Sarge = Hold Right + X, then press L, L, Up, Down, Left, Down.
Jack = Hold Up and press X, A, R, R, Y, A.
Peelgood = Hold Down-Left and press B, Y, Y, A, Y.
Butch = Hold L and press X, R, A, X, R, R.
Ice = Hold B and press Up, L, L, L, Right.
Slyck = Hold Y and press L, L, Up, L, Left, R.
Spike = Hold R and press X, B, B, A, Y, Left, A.