SEGA is planning to release a retail version of Sonic Mania which is titled Sonic Mania Plus and will arrive this summer. The game includes Sonic Mania, Mighty and Ray as playable characters, a new Encore mode, 4 player Competition mode, Holographic packaging, 32-page art book, and more. The game retail version will be available for PS4, Xbox One and Nintendo Switch.
Sonic Mania goes packaged with Sonic Mania Plus! Mighty and Ray join as playable characters, new Encore mode, 4P Competition mode, Holographic packaging, 32-page art book, and more. Summer 2018. pic.twitter.com/4U74kJ7xuG— Sonic the Hedgehog (@sonic_hedgehog) March 16, 2018
UPDATE 4/26/2018 - SEGA has confirmed that Sonic Mania Plus will be launching on July 17th. The company also released a new trailer showing off some of the new additions to the package. Those of you who already own Sonic Mania will be able to purchase the DLC separately.