|Special level, Sonic Mania|
|Number of Acts: 32|
By jumping into the star ring while hitting a checkpoint in Sonic Mania, you will enter the Bonus Stage. Entering requires having a certain amount of rings similar to Sonic the Hedgehog 2 and Sonic 3 & Knuckles. At least 25 rings are required.
The stages are identical to Blue Spheres, the Special Stage of Sonic 3 & Knuckles, and thus the rules are the same. To complete the stage, you must go around the stage and collect all the blue spheres while avoiding the red ones. As a reward for completing the stage by collecting all the blue spheres, the player earns a medal, which will be silver if the player didn't get all the rings, or gold if the player did get all the rings. These medals serve to unlock bonus features such as extra gameplay features or extra modes.
There are a total of 32 stages to complete, with 16 of them being the original layouts from Sonic 3 & Knuckles, and the other 16 being all-new layouts with new color schemes. When all 32 have been completed, Blue Spheres mode will be unlocked, allowing the player to play a randomly generated Bonus Stage a lá Blue Sphere with two styles. In the "Original" style, the stage pieces are the same as those in Blue Sphere, while the "Mania" style adds two extra sphere types originally from the Sonic 3 Remastered proof-of-concept: