Sonic and Knuckle are back in the action. It means a lot of fun for you. The beginning is about an easy story explaining why are these guys in this game. You choose one and collect emeralds or blue Chao creatures in many levels. The level system is a bit confusing in the beginning. You choose one world where are other levels and then you get to the collecting of something. The main part is jumping, nothing surprising. Destroy the enemies, get over pitfalls and collect rings to safe your life. Some Chao guys and emeralds are easy to reach but some are well hidden behind doors.