According to Takashi Iizuka. Sonic Mania came out of the love from the original Sonic series. Christian Whitehead and Simon Thomley(the people behind the remastered Sonic ports on mobile devices) took part in the development of the game.

"Sonic Mania was born out of our fans love of the classic Sonic 2D platform games. This type of collaboration is a first for Sega and we hope everyone will be both surprised and delighted by this title. Sonic Mania has been a passion project for the entire team and we look forward to sharing more details about it later this year. Having the game actually playable at the event itself tonight was testament to the dedication of the team behind it.”