Ring Time Challenge 2 is the fifth and final Challenge Act of Crisis City Act 1 in the console/PC version of Sonic Generations. It is unlocked after clearing every Stage in the Modern era and is playable only as Classic Sonic.
This Act takes place within a highly modified version of Crisis City Act 1, consisting mostly of rising, narrow pathways filled with enemies and Spinning Platforms. The player is given Ring Time in order to collect enough Rings to complete the Act.
In this Challenge Act, the objective is to reach the Goal Plate at the end of the course after collecting at least one hundred Rings.
The player begins the Act on an elevated building. After jumping down, they must use Ring Time to turn nearby enemies into Rings and collect them. From there, they must travel to the right until they enter a building, and activate Ring Time whenever they come to an enemy. After getting far enough into the building, the player will encounter Spinning Platforms, and will eventually need to activate a Switch to move forward. The player should then continue traveling upward (while using Ring Time on enemies) until they reach the Goal Plate.