And a physical release that actually includes a Switch card, hallelujah.
http://www.nintendoworldreport.com/news/46725/sonic-mania-expansion-announced-new-title-teased
Sonic Mania will be getting an expansion this summer, with new friends and a new format.
Announced at the South by Southwest festival in Austin, the expansion will add new stages, modes, and two new playable characters. Mighty the Armadillo and Ray the Flying Squirrel, a duo who have appeared in various spinoff material and an arcade Sonic game, will join the cast. At the same time, a new special edition known as Sonic Mania Plus will be released, which will include the game and expansion on a Switch card in addition to an art book and holographic packaging.
At the end of the presentation, a new Sonic title was teased that was not a sequel to any prior Sonic game. The teaser video played the sound of a revving car before revealing a "R" before fading to black.