Sonic, Tails, and Knuckles race through classic levels from "Sonic 2," "Sonic 3," and "Sonic and Knuckles" in order to defeat Dr. Robotnik.Sonic, Tails, and Knuckles race through classic levels from "Sonic 2," "Sonic 3," and "Sonic and Knuckles" in order to defeat Dr. Robotnik.Sonic, Tails, and Knuckles race through classic levels from "Sonic 2," "Sonic 3," and "Sonic and Knuckles" in order to defeat Dr. Robotnik.