I love being a turtle!

By all measurements, Teenage Mutant Ninja Turtles 1987 was a huge success.  Its cartoon spanned 10 seasons with 193 episodes.  That's a hell of a run.  

It adapted the darker comic (which was a hyper violet parody of trendline in comics in the '80s, "grim and gritty") into a more kid-friendly, humorous tone.  "Cowabunga!"  "Heroes in a half shell!"  and so on.

That's not to say it was "bad," there are great episodes from the beginning to the end of the series (but as it was, there was also a lot of bloat and bad episodes as well, the quality had wild swings).  

And it had a HUGE cultural impact.  Action figures!  Cereal!  Video Games!  T-Shirts!   A music tour!  Movies!  and more!  

There is an inflection point, perhaps the second movie, Secret of the Ooze (1991), where Turtlemania began to wane.  Over-saturation, creative fatigue, and children aging out pointed to the end of Turtles at the forefront as the '90s got rolling.

However, the toon itself began to experiment with things to come.  

Kids who grew up with TMNT were now tweens or teens.  The show tried to evolve with them.  Darker, more serialized cartoons like X-Men: The Animated Series, Gargoyles, and Spider-Man: The Animated Series were dominating the landscape.  TMNT needed to adapt or fade.  

Bebob and Rocksteady in bunny outfits wouldn't cut it anymore.

Tone Shift:

The "Red Sky" seasons (Seasons 8–10, airing from 1994 to 1996) were a deliberate tonal pivot, an attempt to recapture older fans and respond to shifting pop culture trends in children's IP.  

The skies were literally an apocalyptic tone/a red hazy overcast.  Gone were the bright, blue skies of earlier seasons.   This world was grimmer, more serious.  

The humor was dialed down, and Bebop and Rocksteady were given reduced roles even when Shredder and Krang were involved.   Shredder even destroyed the Channel 6 building to really drive this home.  He was colder, more ruthless.  April O'Neil became a freelance reporter and was given new, more professional clothing. 

This pointed to higher stakes, and the turtles faced other villains; there was fleshed-out story arcs and more morally complex situations.  Less slapstick, more tension.

There was a sense of finality, especially in Season 10.  

The turtles were fighting for Earth's survival against Lord Dregg, they firmly defeated Shredder and Krang, learned their true purpose from Splinter (not to defeat villains, but rather to do good), and in the finale were made equals to him (no longer students).  The show did reward those who stuck with it to the end.  There just wasn't a random last episode.  It provided a proper ending.

Red Sky seasons were appreciated in hindsight for their ambition and overall quality.  But commercially, they couldn't reverse the decline.  

The toy line was losing steam, and the franchise lacked a unifying reboot strategy.  

Some fans preferred the old tone, others the new tone.  Then, there was the fact that fan favorite characters were written out (such as Irma), and some of the story choices were considered clunky (the Turtles' further mutation).  Others did not like Lord Dregg replacing Shredder and Krang as the main villain.  

2003 Turtles:

Great children's IP, really great children's IP, is multigenerational, and what eventually happened was a new cartoon.  

The 2003 Teenage Mutant Ninja Turtles series was the franchise's strategic/firm reset, a full-on campaign relaunch that re-centered tone, lore, and most importantly, unified audience alignment. 

The Red Sky seasons from the '87 series were a flawed late-stage tonal pivot, but with the 2003 reboot, there was a clean slate.  Leaner, meaner, and narratively coherent.  There'd be no audience fracturing because the show would have a more mature tone from the start!  

It drew heavily from the original Mirage comics, restoring the darker, more serious tone and moral complexity that had been diluted in the '87 series, films, and other marketing of the Turtles over the years.  It wasn't "adult," of course, but rather a take that would interest older children, in that 10-13 age range.  It was, say, more Mirage-lite/Mirage-teen.   

2003 Turtles did have their own backstory and mythology that was individualized from the Mirage comics.  Some people to this day hate that Shredder turned out to be an Utrom, frankly, I've come around to it.  Given his backstory and motivations, a case can be made that this was the single most dangerous and evil version of the character.

Instead of one-off antics, it embraced long-form story arcs.  The Shredder's true identity, the Battle Nexus, the Utrom reveal, and the gradual rise of Karai were all meticulously developed.  It respected continuity and rewarded attentive viewers.

Building a better April O'Neil:

April, in the 2003 series, started as a lab assistant to the ever-arrogant Baxter Stockman, not a TV reporter.  This aligned her more with the Turtles' origin and tech-heavy plots.  

In the 1987 series, April was often seen chasing stories or being a damsel in distress, and provided fan service.   The same coding would be seen in many '80s boys' programming.  Get young boys to crush on the female lead as a further enticement to consume the programming.  

She was reminiscent of Lois Lane in her character traits.  April was typically curious, courageous, and constantly involved in action, sometimes to a fault.  She had a type-A personality but was also very accessible and relatable, charming, and often served as a voice of reason.  1987 April would likely appear on lists of '80s cartoon crushes, alongside characters like Lady Jaye, Jem, Teela, and Cheetara.

Certainly, 2003 April was brave just as 1987 April, but this April was more resourceful in ways the old April couldn't be.

The science background with 2003 April allowed her to be more involved directly with research, infiltration, and tech (as well as providing fan service, love the midriff, April). 1987 April, she had her camera, and that's more limiting.  Further, this April was more directly coded as "big sis"... emotionally mature, nurturing, friendly, and intuitive. 

2003 April overall, operated more as a "real" person who chose to be a part of the Turtles' world out of loyalty and conviction.

It was, also, the first proper adaption of her romance with Casey Jones.  

Star Trek 3:  The Search For Splinter:

At the end of season 1, the Turtles defeated Shredder, but their master, Splinter, was injured and then vanished.  This created the first big arch in season 2, with them searching for Splinter, and their investigation led them to the T.C.R.I. building, a mysterious tech corporation that was secretly run by the Utroms. 

Both April and Casey assisted the Turtles in gaining access, but as the episodes progress, the Turtles discovered a wealth of information about the Untrons and Shredder, while April and Casey remained outside in the Turtle Van (they aren't relevant to the reveals). 

Additionally, the various uses of the teleporter at the T.C.R.I. building attracted the attention of government officials, and had the military surround the building.   

2003 April pays homage to 1987 April:

Inside the dimly lit Turtle Van, April rifled through about, fingers brushing past gadgets and gear until she found what she was looking for.  A yellow jumpsuit, folded and faded, but still intact.  

Casey, seated nearby, caught the motion and immediately turned away, shielding his eyes with one gloved hand.

April's voice was steady as she zipped it up.  "We can't sit around anymore.  We need to know what's going on in there."

"The authorities won't talk to us," April said, "but they might talk to a TV news reporter!"

She stepped forward, boots echoing lightly on the van's metal floor, and struck a pose near the front seat.

"How do I look?" she asked.

Casey turned, squinted, and gave her a once-over. "Ahh... great if you're removing toxic waste."

April rolled her eyes and punched his shoulder.  Not hard, but enough to make him flinch.

"You're no help," she said playfully.

"Ow!" he grunted, rubbing the spot.

She handed him a makeshift camera cobbled together from spare parts and duct tape.  "Can you at least be my cameraman?"

'Casey took it with a sigh. "Do I have a choice?"

"April O'Neil, Channel 9 News.  Ah... Channel 6 News."

The Turtles and Splinter did, finally, get out of the building, and Leonaldo did playfully ask, "So, what's with the get up?  You a news reporter?"  and April scoffed, "Ha!  In another lifetime maybe..."