Yes! After completing all three acts alone on each zone in game world, you receive a chaos emerald.
There are 7 main "planets" which represent 3 levels in each.However there's also special stages, Terminal Velocity, and a secret boss in Sonic colors DSThe planets include:Tropical resortSweet Mt.Starlight CarnivalPlanet WispAquarium Parkand Asteroid Coaster(as well as Game land)
unfortunately, you don't. unless you hack it to unlock all of the Sonic Simulator stages, you don't.
2-player mode is in a special area called the Sonic Simulator. It has a metal Sonic face when you choose it.
You have to complete all of the special stages, then you will unlock the final boss, the time eater.
If you mean special stages, they allow you to collect chaos emeralds. Get all 7 for a special ending.
Get all the Chaos Emeralds by completing the special stages that you can enter into by going into a level and finding one of those spinny things that you boost on.
In the Sega Megadrive game you had to collect all 7 chaos emeralds by clearing special stages. The emeralds enabled you to turn into super Sonic when you collected 50 rings.
Sonic Colors happened in 2010.
Sonic Colors
In any level, there is a wierd circle with a star in the middle. You can grab that but you need boost to use it, you boost on that and after a bit it will launch you in a special.
There is no Sonic Heroes 2.