Broken Base: The canonicity of this portion of the franchise. While the idea of the teams meeting each other is great, there are some, both within the fandom and with the creators of the various seasons, who feel that bringing them back for series like this just cheapens the endings to their series and with them forever stuck as their initial ages isn't fair, unlike their Kamen Rider and Super Sentai counterparts, who are allowed to be seen aged up if the actual actor returns.
Family-Unfriendly Aesop: New Stage 2 seems to be saying "Hey kids! You can make friends by being really mean to them and using them for your own ends! They'll still save you even if you've done nothing to deserve it!"
Faux Symbolism: New Stage 3's premise. It's about a mother tapir who wants to protect her shy, sensitive child from all bad things to the point of going too far, becoming completely overbearing, and hurting others in the process. Doesn't this sound like a very thinly veiled Take That! to Moral Guardians and the whole "protect the children" idea?
Heartwarming Moments: The little Slice of Life sections from the dance segments in Spring Carnival. For longtime viewers of the series, seeing some of their favorite characters in their own universes really brings home the nostalgia factor. Here are some examples:
Splash Star: Saki and Mai are losing a volleyball game but are spurred on by their cheering friends and are able to turn the game around. The girls then engage in a celebratory hug. And for meta-Heartwarming points, the cameo appearances of Michiru and Kaoru.
Fresh: On top of bringing back the first ED theme, which alone can count as a meta-Moment of Heartwarming, the Cures are seen giving hearts to many of the side characters, including their families, Kaoru, Westar, Soular, and some of Labyrinth's children. After the dance, Love says that while Setsuna has been absent for a while due to reforming Labyrinth, she, Miki, and Inori still consider her to be their precious friend. Setsuna smiles in response.
Heartcatch: Cologne, Yuri's long-forgotten fairy partner, is shown on-screen for the first time since 2010. Even Yuri is moved to tears.
Suite: Ako smiling with the purified Noise and giving her mom a bouquet of flowers, followed by the rest of the Cures jumping in for a group hug. Hibiki playing piano with both her mom and dad looking on can also be one due to how little time either can spend with their daughter.
Smile: Miyuki and the gang get together to celebrate Candy's birthday. Needless to say, there were smiles on both sides of the fourth wall.
Doki Doki: Rather than a Slice of Life segment, Doki Doki plays a montage of moments from its run, including Aguri and Eru holding hands in the festival episode and Mana giving Regina a hug during the final battle.
Happiness Charge: Megumi and the others hold a "Happiness Party", complete with the flowers cut to look like Ribbon and Glassan and Blue making an appearance, presumably to visit the Cures after helping Red restore his planet. Yep, there's plenty to be happy about.
The ending to Everyone Singing - Miraculous Magic finally has Cure Echo join in the Dance Party Ending.
Like You Would Really Do It: DX3's climax brings the Cures one last chance to transform and save the world at the cost of never being able to see their mascot friends again. Seeing as how the movie was released towards the beginning of Suite, there was no way they'd permanently lock away the Cures' ability to transform.
Moment of Awesome: Seriously, why were these 70 minutes each? There could have been even more ass-kicking!
The Zakenna airplane. Which Black and White promptly kick into the distance (while said plane is still several hundred feet up)
For most of the battle sequences, each team only fought strategically alongside their respective teammates, and "mixed combat" was more of a side-effect... until Cure Dream and Cure Bloom punch a Kowainaa monster in the face TOGETHER! (While Egret and Lemonade are busy surviving.) The power of earth and dreams! UNITED!!
Milky Rose punching the ground and leaving a LARGE crater for the Big Bad to slip in.
In the sequel, she briefly goes into mascot form to dodge an attack androundhouse sucker punch her opponent back!
In the third movie, when everyone ran off to make space on the Whack-A-Monster, Cure Moonlight just stood there unfazed like a complete badass before she whacks the monsters singlehandedly and inspiring the rest of the Cures to get on whacking (lots of monsters eventually).
In New Stage 2, after Cure March attempts a March Shoot at the Big Bad who simply dodges it and gloats how it's direct and lacks technique, Cure March proceeds to do a Macross Missile Massacre version of her attack after saying "I'll give you all the direct attacks you want!"
Narm: the epilogue of the third movie was supposed to be serious but ended up being happy instead.
The ending credits too. It was supposed to be really sad, but the happy ending music kind of ruin the mood.
Miraculous Magic has its tendency to animate the singers with excessive gestures like in stage theater. While the overly dramatic gestures are necessary in theater because of the distance between the stage and the audience, seeing the florist at the opening moves up close is hilarity-inducting.
Surprisingly Improved Sequel: The teams are seen interacting for some of the sequel (most notably the Heartcatch and Fresh teams), which is an improvement over the Stealth Hi Byes of the first movie. However, it's only those two teams that really interact for more than a few minutes, so mileage will vary.
The Scrappy: Cure Echo is disliked among a group of fans for taking away focus from the other cures for the majority of the movie and doing even less than Shiny Luminous. It's made worse by the fact that she doesn't even become a Cure until the final 10 minutes of New Stage 1, and doesn't even fight, all she does is give Fuu-chan a cooldown hug then de-transforms.
Nozomi's farewell to her dreamworld in New Stage 3.
Seperated and demoralized, Miracle and Magical lament their powerlessness against the overpowering adversaries and the large shoes they have to fill as Precure as they cling to each other's non-existent presence in Miraculous Magic.
The entire world is on the line...
...while all I can do is failure.
Tough Act to Follow: DX3 delivered so much, be it actions, speaking parts, sweet, awesome and sad moments that many people felt the New Stage movies, while pretty good on their own, were a little lacking when compared to the DX ones.
Too Soon: A tsunami scene (the flood of various fairies from other worlds) was cut from DX3 due to the 9.0 magnitude Sendai earthquake and tsunami. It was later restored on the DVD release, however.
What Could Have Been: Teaser pictures for New Stage showed off a number of things including the Smile team under attack by Fusion over the city, Cures Peach, Blossom, Melody and Echo evading attacks by Fusion and a picture of Ayumi with Hibiki, Tsubomi and Love hinting that Ayumi would have known who the Cures were. None of this happened.