Switcheroo is the third Challenge Act of Crisis City Act 2 in the console/PC version of Sonic Generations. It is unlocked after clearing every Stage in the Modern era and is playable only as Modern Sonic.
In this Challenge Act, the objective is to reach the Goal Ring at the end of the course.
The first section of the Act involves simply hitting Switches to progress, while the rest requires the player to choose from several of them at a time in order to secure a path ahead. Once the player reaches the section with several switches, they must hit them in the following order: The switch on the left to activate a platform to reach the upper section, then the switch on the right to activate the barriers they previously jumped through. From there, they must hit the switch on the left, and can then hit the next switch on the left in order to grab the Time Bonus before hitting the lone switch on the right wall. After jumping down, the player must hit the switch on the right, run across the two switches they see to activate more platforms, and then hit the last switch of the lower stretch on the right. The next switch must be hit on the left, the next one must be on the left again, and the next switch on the side of a platform must be pressed while avoiding the one on top of the platform. The player must then jump across the currently activated barriers and hit the switch on the upper ledge, and they can then drop down and hit the spring to be sent flying into the Goal Ring.
An alternate route can be taken at the beginning if the player carefully jump dashes onto a narrow platform and air boosts forward, where they will be taken into a Four-way Cannon which they must quickly aim upward and fire. This will take them above several more hazardous sections of the Act before progressing normally.