To unlock Super Sonic, you have to collect 180 Red Rings, and then clear every Sonic
simulator stage. You have to collect the Red Rings from the 36 regular acts. Once that's
done, you unlock the second and third simulator acts. You must clear all 21 of those
Unlock The True Ending
Complete Terminal Velocity with all of the Chaos Emeralds, and then after the credits go
back to the game - After the video cut-scene, you can play the final stage and fight the
Unlock Nega-mother Wisp Final Stage
If you successfully complete Terminal Velocity with all emeralds, then after the credits have completed, return to the game. After a quick cut-scene, the final stage with Nega-Mother Wisp will be available at the very top of the world map.