Some new details emerge about Sega’s upcoming Sonic the Hedgehog 4: Episode II on the Xbox Marketplace although they weren’t supposed to. The box-art was uploaded with new details such as online and offline co-op which is looking to bring back the classic Sonic & Tails 2-player action from Sonic the Hedgehog 2. There was also some screenshots that leaked but were quickly taken down. Fortunately, someone on NeoGAF copied the screenshots and you can find them and the box-art after the break. Here’s the plot description from the Marketplace:

The Sonic 4 Saga continues as Sonic reunites with Tails for all new collaborative play! Following the events of Episode I, Metal Sonic has returned to form a formidable alliance with Dr. Eggman! To face this new threat, Sonic will have to call upon an old friend to help him save the day! Joined by Tails, utilise ingenious combination moves and race across four brand new Zones, in order to put an end to their evil plans! Play alone, or with a friend locally (and online), in an evolution of Sonic 2’s collaborative gameplay! Unleash Sonic and Tails’ devastating joint attacks and combination moves to fight the united force of Metal Sonic and Dr. Eggman. Episode II features an all new game engine, bringing you updated physics and an original graphical style as you race through four unique Zones and a new Special Stage.