Sonic's Secrets: Ballz.

To play int the Green belt tournament, at the Title screen, press:

A, A, Down, C, B, A, Up, Up, Down

You will hear a noise and the music will stop confirming that you have entered the code correctly.

To play int the Red belt tournament, at the Title screen, press:

A, Down, Down, B, B, B, C, Left, Right

You will hear a noise and the music will stop confirming that you have entered the code correctly.

Hyper Mode.

At the title screen press A nine times to enable Hyper Mode (2-players only.)