The Power Rings are almost identical to normal Rings except that they are rainbow-colored instead of gold. Accordingly, they are Rings which have accumulated a special energy as a result of being out in nature for a long time, giving them special powers; while normal Rings can rejuvenate a person's powers and abilities at best, Power Rings enhance them, make anyone extremely powerful if enough are collected. Power Rings also have the ability to repair machinery if enough are collected; otherwise, the effects are only temporarily.
When Zazz returned to get revenge on Sonic the Hedgehog, he began stealing Power Rings to make himself more powerful. When learning of this, Team Sonic began tracking Zazz down to get the Power Rings back.
In gameplay, Power Rings can be collected in the stages and from damaging bosses, but only amidst the raid bosses during the "Zazz Raid Event". Like Rings, as long as the players possess even one Power Ring, it will protect them from losing the stage upon taking damage. When the players takes damage, they will drop all of the Power Rings collected, making them vulnerable to attack. Sometimes, Super Rings holding ten Power Rings also appears.
↑Sonic Team (February 25, 2015). Sonic Runners. iOS. Sega. Area/level: Zazz Raid Event. "Tails: He says that Power Rings are special rings which have accumulated a special energy as a result of being out in nature for a long time. Apparently, they can make anyone who collects enough of them extremely powerful..."