The official DLC pack for TMNT: Shedder's Revenge is set to roll out in 2023. The downloadable content will add a new game mode, character colors, and some new playable characters. Leading the news is Usagi Yojimbo, an occasional ally of the Turtles who have crossed over with them in the past. 

The following is from Dotemu's press release:

Chaos! The Neutrinos crash the Turtles’ latest pizza party! The teenagers from Dimension X are in dire need of help: Shredder is seeking to conquer the multiverse itself!

Our heroes need to jump between dimensions and stop Shredder once and for all!

Dimension Shellshock brings new playable fighters, including the razor-sharp Usagi Yojimbo.
The steely rabbit samurai is ready to hop across dimensions to fight evil and witness a new style of otherworldly battles awaiting the Turtles!

Features to look forward to include:

• Explore dimensions in an upcoming new game mode – additional details coming soon!

• New playable characters including Usagi Yojimbo!

• Amazing new tracks by Tee Lopes!

• Exclusive color palettes to unlock. Take a stroll down mutant memory lane with new oozy hues!

Teenage Mutant Ninja Turtles: Shredder's Revenge is currently available for the Xbox Series X, Xbox One, Nintendo Switch, PlayStation 5, PlayStation 4, Windows, and Android.