During the 25th anniversary stream, Sonic Mania was announced and it looks amazing.
SEGA just announced a new 2D sonic game developed by SEGA, Christian Whitehead, Headcannon, and PagodaWest Games. Sonic Mania will have three playable characters: Sonic, Tails, Knuckles and include remixed classic levels in addition to new zones.
Check out the trailer below:
GameSpot also has some gameplay that you can watch:
Sonic Mania is scheduled for a spring 2017 release on PlayStation 4, Xbox One, and PC.