Here's why:
* Different Games, Different Structures: Each Sonic game has its own level structure. Some games use "acts" as part of their level design, while others use different terms like "zones" or "stages."
* Variable Number of Acts: Even within a single game, the number of acts per level can vary. Some levels might have one act, others two or even three.
To know how many "acts" are in a specific round of a Sonic game, you'd need to specify which game you're talking about.
For example, in Sonic the Hedgehog 2, each level is divided into two acts.
Let me know if you have a particular game in mind, and I can tell you more about its structure!