From the trailer below, Mania looks unapologetically old school, replete with chiptune music and the series' trademark hyper-colorful pixel-art style. Three playable characters are on tap (Sonic, Tails and Knuckles) and in addition to a new move like the drop dash and new levels, Mania will apparently put a couple of twists on old stages as well. The only problem is that despite Sonic's expediency, Mania will be late to the series' anniversary party with its "spring 2017" release window.
But hey, with how the more recent games have turned out, fans would probably rather that developers Christian Whitehead -- who has worked on ports and remasters of the franchise in the past -- and Headcannon, along with PagodaWest Games, take their time to get it right.
Update: And for a more modern take, Sonic Team just announced it's working on 'Project Sonic 2017.'
Update two: The PlayStation Blog has a few additional details. Sonic Mania will "reimagine" zones from Sonic The Hedgehog, Sonic The Hedgehog 2, Sonic CD and Sonic The Hedgehog 3 and Knuckles. It'll be digitally distributed, available on PlayStation 4 and Xbox One (at the very least) and have new zones, acts and bosses.