An X post is currently doing the rounds which claims that a Playground Games source has said that SEGA is currently hard at work on a 2.5D Sonic the Hedgehog game. The 2.5 platformer, which is seemingly being developed internally at SEGA, is apparently planned as a 2027 release. This is just a rumour at present and should basically be taken as such.
Rumour: SEGA apparently has a 2.5D Sonic game in the works for 2027

Why would someone at playground games be leaking sega games? Shouldn’t playground games be worried about not getting shut down by Xbox instead
Darn it, I wanted a 2.25D sonic game.
This would be sick ngl
If they got Blaze in a bikini outfit I’m in.. 🤤
Dude, I just played sonic rush last night. Don’t ruin blaze for me.
Sonic Superstars is one of my least favorite Sonic Games of all time and I played every Sonic game, all of them. Sega Having a sequel to that over getting Christian Whitehead shows that they dont care. Get the developers behind Balan WonderWorld again. Only care about easy money. It probably will be a $#&@ Key-Card only anyway.
I just ordered several physical Switch Games on FanGamer. Nine Sols, Pizza Tower, Antonblast, Baba is You, Tunic, omori, and UFO 50. I already own Undertale Physically. 5hey are bringing Hollow Knight and Silk Eong Physically for Switch 2. Gonna pick both dem up. In October I want to get The Physical copy of the Toy Story Roundup Collection, Toy Story 2 and Bugs Life on PS1 were pretty great, comes with Toy Story 3 too, never played that one.
2.5d sonic game I’m in