Instructions
Play through Sonic Heroes and collect all seven chaos emeralds. They are hidden in special stages at the end of the second part of each level. Collect the "special stage key" item during a level to access the special stage. Finish the stages to collect the emeralds.
Defeat the final boss with all four sonic teams, starting with team rose. The colors on the boss's weak point will tell you how to attack. If it is red, do not use power attacks. If it is blue, do not use speed attack. If it is yellow, do not use fly attacks.
Watch the cut scene to confront the secret final boss and become Super Sonic. Collect extra rings in balloons around the area to keep your ring count up.