There are several themed "Zones" to play through in Sonic the Hedgehog 3.
Each one consists of two "Acts" and the second Act ends with a unique boss battle.
The Zones are:
- Angel Island Zone
- Hydrocity Zone
- Marble Garden Zone
- Carnival Night Zone
- Ice Cap Zone
- Launch Base Zone
Each Zone also features Bonus Stages and Special Stages.
Bonus Stages are ways to collect bonus rings and power-ups. The Gumball Machine has you repeatedly hit the switch of a giant Gumball Machine to receive prizes. You must use springs on the walls of the stage to stay in the air. Falling to the bottom ends the stage. You keep prizes won and re-enter the normal Zone at the last checkpoint.
Special Stages are separate to the Gumball Machine stage and are activated by collecting 50 or more Rings in a single Act, then jumping into a giant ring hidden somewhere in each stage. The Special Stages are 3D challenges in which you must collect Blue Spheres while avoiding Red Spheres. Collecting all of the Blue Spheres rewards you with a Chaos Emerald. Collect all of the Emeralds to transform into Super Sonic in Zones after collecting 50 rings.
Sonic 3 is the first game in the series which allows you to save your game and replay any Zone of your choice after finishing the game.