Sonic the Hedgehog 2 is a platformer game where the titular character must rescue his friend Tails after Dr Robotnik's return from vacation. A letter from Tails reveals that Robotnik has captured all the animals on the island, including Tails, and is holding him in the Crystal Egg.
Robotnik plans to use six new robots to stop Sonic once and for all. With this motivation, Sonic sets out to defeat Dr Robotnik again and rescue his friend. The game features Sonic racing through various levels, collecting Chaos Emeralds, and battling against Robotnik's army of robots.