Spheres

Spheres(スフィア Sufia?) are round-shaped, collectible objects that serve multiple purposes. Spheres are only found at the Special Stages of certain Sonic games and essential to obtaining a Chaos Emerald. In Sonic 3 & Knuckles and in Knuckles Chaotix, the player must collect blue spheres while avoiding the red spheres to progress throughout the Special Stage. But in the following games like Sonic Heroes, this rule has changed.

Sonic Heroes introduces multicolored Spheres the player can collect for the Special Stage's variants of Bonus Challenges and Emerald Challenges. There are three types of spheres with the same purpose; to power up the Power Dash. The first are the multicolored spheres, which are in groups or in long strings. These spheres only give a small amount of power to the Power Dash. The second is the slightly larger blue spheres with star prints called, Super Spheres. These spheres equal to ten multicolored spheres in power. The third are red colored spheres with star prints on it called, Score Spheres. These double the dash power by ten fold of the multicolored spheres. The Nintendo 3DS version of Sonic Generations also follows these principles. In the Nintendo DS version of Sonic Colors, only the red, blue, and yellow colored spheres are featured in the game. The player has to collect these spheres in a certain order and avoid the others or else it will subtract the sphere the player is collecting. The Super Spheres also makes an appearance in this game with its function of increasing the number spheres the player obtains. But in Nintendo 3DS version of Sonic Lost World, there are only the red and blue spheres the player must collect.