Radical City is the second level made available for play in Sonic R. It contains two Chaos Emeralds and collecting all five Sonic tokens will allow you to race against and unlock the Tails Doll.
Instruction Manual Description
||This course is plenty wide. Gaps in the railing aren't just accidental breaks! Waterways look like slow going at first, but they can save you some time if you know which turns to take. And speaking of turns, there are a couple of tight ones to add to your fun. Ever wondered what it would be like to be a pinball?