Oh, it turned a corner alright... It turned around right back into the dumpster behind the alley from whence it came after Mania with Forces, Team Sonic Racing and this movie.
This isn't anything new, by the way. People thought Sonic had turned a corner following Generations almost a decade ago, but then all of that was squandered immediately with Lost World and Boom. It seems Sonic only really "turns a corner" whenever copious amounts of nostalgia is involved.
While it is true that Mania is quite literally the only good Sonic game in recent memory, I also didn't like the way Iizuka handled the project, practically mandating that the game be 70% old remixed stages bloated to hell and high water and calling it Mania, like as if to show some deep-seated disdain for the fanbase. Unless this supposed sequel is made up entirely of new stages only and isn't meddled with by him (Like how Mania was originally supposed to be called Sonic Discovery and everything), then I can't say I am excited nor interested to see what other new corner awaits the blue blur.