Infinite Boost
When you collect ALL the red special rings in the 6 main zones you will be rewarded with an unlimited boost gauge at the 'Options' menu. The unlimited boost gauge cannot be used in Time Attack or Versus modes.
Unlock Nega-Mother Wisp
Complete Terminal Velocity with ALL 7 Chaos Emeralds, then after the credits have finished return to the game. After a brief cinematic the final stage with Nega-Mother Wisp will be available at the very top of the world map.
