Instructions
Back up to the farthest left edge of the platform or strip Sonic is standing on. Sonic builds up speed much faster if he has a clear "runway."
Run to the right, heading for springs, loops or ribbons. These increase your forward momentum and propel Sonic faster than he could normally achieve running in a straight line.
Jump over or through enemies. You aren't required to attack enemies, so avoid them. Otherwise, getting hit stops your momentum and makes you vulnerable by causing you to lose all your coins.