Embark on an adventure to the Northstar Islands in an all-new version of Sonic's classic 2D platforming adventures. Play as Sonic, Tails, Knuckles, or Amy and master never-before-seen emerald powers that will allow you to dynamically move and attack like never before. Explore wonderful, undiscovered lands alone or with up to three other players, and stop Dr. Eggman, Fang, and a mysterious new enemy before they turn the island's giant animals into badniks! – A classic reimagined: the fast-paced, two-dimensional platformer we all know and love, with new 3D graphics, new powers and abilities, new scenery, and new ways to play! You don't know the classic Sonic yet! – Play as your favorite heroes – Sonic, Tails, Knuckles or Amy – and use their unique abilities as you traverse the Northstar Islands. Help them stop Dr. Eggman, who has teamed up with his former enemy, Fang, and a mysterious new armored foe.- Harness the power of the Chaos Emeralds: clone yourself, swim up waterfalls, transform your character, and more.- Group Up Smarter: For the first time, you can complete the entire Sonic campaign with three other players in local co-op for up to max. 4 players – with the option to join and leave the game at any time! – Challenge players from all over the world: compete on-site or online with up to eight players in the new battle mode!