checked-no =>Secret Stage Mode: Once you've beaten all seven of the Special Stages, go to the main menu and press U [R] D [L] R L. =>Sound Test: Complete the final level to make the Sound Test option appear. =>Boss Time Attack: After you've earned a gold medal in every level and boss battle, go battle Nonaggression. After the credits play, Boss Time Attack will be available. =>Extra Characters: To unlock the extra characters, you must have Sonic acting as the leader when you complete the listed stage. * Knuckles: Complete Zone 2, Act 3. * Cream: Complete Zone 6, Act 3. * Amy : Complete Zone 4, Act 3.