>>96699249IDW TMNT.
Well, basing it off Kingdom Hearts 2 formula, two world visits. First visit ends with Shredder's death. Second visit theoretically ends with the conclusion of the Demi-God Family Arc.
After clearing the world? You get access to optional boss fights with the other villains of the franchise like Bishop, Krang, Null, Old Hob, Karai, etc. Given Kingdom Hearts 3's engine is powerful enough for many allies, all the turtles can show up in the gameplay.
That should sum it up. You know, it would be actually kind of fun to have Sora chill with the turtles.
