- You may be looking for a different Challenge Act, Amy: Topsy Turvy.
Topsy-Turvy is the third Challenge Act of City Escape Act 2 in the console/PC version of Sonic Generations. It is unlocked after clearing every Stage in the Dreamcast era and is playable only as Modern Sonic.
In order to complete this Challenge Act, Sonic must reach the Goal Ring before time runs out. The player begins directly before the building which Sonic must run down. After doing so, the player must get across the many spinning platforms and horizontal bars that lie in their path, making it more difficult to get through the section, while avoiding the enemies that will attack them. From there, the Act mostly continues as normal, and the player will find the Goal Ring at the foot of the staircase in the 3D section at the end of the course.