https://www.gamespot.com/articles/sonic-mania-plus-adds-characters-modes-on-switch-p/1100-6457485/

Sonic had arguably been in a down period for some time, but last year's Sonic Mania was widely regarded as a return to form for the hedgehog. That digital-only game is finally set to get a physical release, but not just for the existing game. Sega has announced Sonic Mania Plus, a physical re-release of Mania that introduces some new content and features.