Had it been on HBO/MTV in the '90s
For a brief while there was a moment when animation was beginning to once again be largely accepted as a medium for both children and adults in the Western world. The '70s began giving us adult animated films, with the '80s continuing an increase in popularity.
Then when The Simpsons debuted, along with the rise of cable tv, it bashed open a wonderful wealth of opportunities for the art of animation to further explore possibilities beyond the usual child-consideration that had wrongly, and foolishly, been tainted upon wide audiences since Saturday morning cartoons of the '60s sledge-hammered the scene.
Felix the cat either getting drunk or committing suicide had been long forgotten, and the likes of Bugs Bunny or Mickey Mouse could often, unfortunately, be misinterpreted as silly child fodder by the masses.
I don't expect blood and guts and swearing, I just would appreciate a well-written story with plenty of time invested in the nurturing of the characters along with the world around them, something that can either be absent or restrained when children are the viewers in mind.
Half-hour per episode, 8 episodes a season, 3 seasons total could be plenty to tell a story centered around our heroes in a half-shell.
Let's have Splinter dead. The first episode is a bit reminiscent to the first comic, only, Splinter goes with them. He wouldn't want his sons to avenge his own business, he'd give it his all while his sons go up against the foot clan.
After a brutal, hard-fought battle, Shredder ends up killing Splinter, our 'Turtles desperately attempt to battle past the hordes of foot soldiers to reach their father/sensei in time, with no luck.
Giving the audience a strong reasoning for the 'Turtles bitter rivalry with Shredder. In addition to what he had already previously done to Splinter's sensei. In most iterations, the 'turtles mainly go after Shredder for Splinter, now they've got their own agenda, all while coping and trying to stay together as a family.
This theme would follow through the first season, ending with ole Shred-head biting the dust.
April or Casey wouldn't be in the first season. We, the audience, needs to experience the isolation the 'turtles have with the world. That growing sense of detachment. With the 'Turtles only connection with a human being tied into the murder of their father.
The second season would be exploring where they came from and who they are. With connection to the human world, to life on Earth, coming a little clearer with the introduction of Casey and April.
It would be largely centered around the 'Turtles in Space' concept.
The first two episodes dealing with breaking into TCRI. Perhaps on the lower levels there would be human scientists who are unaware of the aliens among them. Baxter Stockman would lead the specific team that has April O'Neil.
April, naturally, ends up in space with our heroes. With her scientific knowledge combined with Donnie's brains, they end up deciding to work together to get home.
Episodes 3-7 in space, season finale finding a way out of TCRI without being detected by the on-coming humans. Baxter may end up playing a part in the difficulty of getting out of the building.
With the 'Turtles having fully accepted their Master/Father's fate, discovered and accepted their origins, and human world coming a little clearer thanks to April, we walk into the 3rd season doing the city-at-war arc. Maybe extend the season to 10 or 12 episodes to fully accommodate the story?
That'd be beautiful. We've seen the 'Turtles grow and come together as a family, while Karai only has herself, remaining in the dark on isolated vengeance. Mirroring the contrast and broadening the strength and importance of loved ones sticking together and showing support in times of grief or suffering.
Casey Jones may finally come along for the fun. With the city falling apart, we need some whack-job vigilante lending a helping hand.