The Gunk is currently scheduled to hit Xbox One, Xbox Series X and Windows 10 PC in Fall 2021. In a statement, Thunderful CEO Brjann Sigurgeirsson explained that this is a full-fledged exclusive and the reason was of a technical nature.
"New IP, new heroes, a new development engine, and an extra dimension. We’ve had to keep this close to our chests for quite some time, and as always it’s a relief to announce to the world what we’re working on. We’re of course very excited.
A bit into the development process it became obvious that The Gunk would be very hardware-demanding. We’ve always managed to keep our games lean, but The Gunk is all bells and whistles about to explode spectacularly. We had to make a choice: either we quiet it down considerably, or we go talk to the guys with the most powerful hardware. We decided to go talk to the guys with the most powerful hardware."