- 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 before time runs out. The level contains a huge absurd amount of Horizontal Bars and Spinning Platforms, which Sonic must use to finish the mission. There are also enemies such as the Gun Hunter and the Gun Beetle. Once Sonic reaches the Goal Ring in time, the mission is completed, and the player is ranked according to his/her time.