Technically we already had a gritty TMNT title of this nature
-It had the cartoon cast but the art direction was a bit darker
-It had Bebop, Rocksteady, Shredder and the Technodrome
-It had the Turtle Van and Turtle Blimp
-You could run over Foot Soldiers in the Turtle Van and shoot missles at tanks and barrier
-You could explore the buildings and sewers of different cities; it was open world!
It has some crappy parts (like certain jumps), but on the whole, TMNT 1 for NES is a decent game
More people should play it