Super-Speed Stage

Mach Speed Sections are a game mechanic in Sonic the Hedgehog(2006), which is the game's unique variant of auto-running.

Description
In certain levels, Sonic will suddenly speed to nearly absurd speeds. In this mode, the player only controls Sonic by moving left or right, and jumping. These sections were one of the few things that were carried on to Sonic Unleashed. What made these sections difficult was that if Sonic were to touch anything while running, he lose rings, or die. And because of the already poor programing, these sections are usually unfairly difficult.