It was the start of the tutorial, where Tails and Robotnik would teach each other the basics of this new kart called a "Ring Racer." Although, Robotnik has some different plans. He drove backwards, revealing a hidden teleporter to "Test Track."

Tails: "Hey, where are you going?"

Robotnik: "I'm going to the testing simulation, to see how this works. I know how to use a kart, you know."