Adventure through the mystical Northstar Islands in this all-new take on classic 2D Sonic high-speed action platforming. Play as Sonic, Tails, Knuckles, and Amy Rose and harness all-new Emerald powers to move and attack in dynamic new ways. Navigate gorgeous, never-before-seen environments solo or with up to 3 other players and stop Dr. Eggman, Fang, and a mysterious new adversary from converting the islands' giant animals into Badniks before it's too late! A new Spin on a Classic. The 2D Sonic high-speed sidescrolling action platforming you know and love, reimagined with fully 3D graphics, new powers and abilities, an all-new setting, and new ways to play! You've never played classic Sonic like this before! Play as your Favorite Characters. Choose from Sonic, Tails, Knuckles, and Amy Rose and take advantage of their unique abilities to blaze a path across the Northstar Islands as they race to defeat Dr. Eggman, who has teamed up with an old nemesis, Fang. Harness the Power of the Chaos Emeralds. Multiply, swim up waterfalls, change form, and more with the powers of the Chaos Emeralds. More Friends, More Fun. For the first time ever in a Sonic game, play through the entire campaign with up to 3 other players with drop-in and drop-out 4-Player Local Co-op. Features Classic Sonic, beloved side-scrolling action, reimagined in 3D with new powers, settings, and playstyles. Play as Sonic, Tails, Knuckles, and Amy, each with unique abilities, racing to defeat Dr. Eggman and Fang. Harness Chaos Emeralds' powers: multiply, swim up waterfalls, shape-shift, and more. Experience Sonic's 1st-ever 4-Player Local Co-op campaign, drop-in and drop-out with friends.