What you have to do is finish the game get all the chaos emaralds [on the bonus stages] complete th game with them all or it will not work. Then when you jump whilse in the air press jump again and...
First you need to collect all the Chaos Emeralds. The way to do this is you need to find the giant Golden Rings hidden in the Acts. When you jump in it you will go into a 3-D special stage. If you...
Collect the 7 Chaos Emeralds before the end of Launch Base Zone, then in Mushroom Hill, Knuckles will run out of a tunnel (Can't miss it). Go into the tunnel and you will see a multicolored ring...