There are several themed "Zones" to play through in Sonic the Hedgehog 2.
Each one consists of two"Acts" and the second Act ends with a unique boss battle. The exceptions to this are "Metropolis Zone" which has three Acts and "Skychase Zone," "Wing Fortress Zone" and "Death Egg Zone" which all have one Act.
The Zones are:
- Emerald Hill Zone
- Chemical Plant Zone
- Aquatic Ruin Zone
- Casino Night Zone
- Hill Top Zone
- Oil Ocean Zone
- Skychase Zone
- Wing Fortress Zone
- Death Egg Zone
There are also Special Stages which are activated by collecting 50 or more Rings in a single Act, then jumping into spinning ring of stars which appear above checkpoints located in each Zone. The Special Stages are 3D challenges in which Sonic and Tails run forwards into the screen, attempting to collect the target number of Rings to be rewarded with a Chaos Emerald. Collecting all of the Chaos Emeralds unlocks the game's second ending.
