The CG effects used in season 1 and 2's transformation sequences was heavily criticized by fans as ugly and jarring. Season 3 featured hand drawn transformation sequences that took many cues from the original 90s anime transformations.
The lead art director for the 90s anime has been hired to direct the art team on the Dead Moon Circus movie after general criticisms about the art style used in Crystal.
Act 19 and 22 have adapted the expressive faces from the manga's humor in such a weird fashion that it ended up as this, to put it simple: They draw the expressions with the original scene's background on it, and then put that under a frame that's based on the manga's background for that moment. In other words: The show makes a Ba-Dum-Ts! joke to itself. Compare: Manga◊ vs any other episode of ''Crystal''◊ vs Act 19 and 22◊.
Tellu's transformation in episode 6 of Season 3. It just... happens. She knocks all of the Inners down with one attack, charges at Chibi Moon, and is immediately killed by Pluto with no further comment. (A result of Crystal Bowdlerizing the original manga scene, where her mutation was caused by Chibi Moon's attack.)
Contested Sequel: Rather "contested adaptation" in this case. Fans are pretty much split down the middle if this one is better then the 90s version or not. One side like that it follows the manga more closely, doesn't have filler and has great animation. The others side hate the characterization in this feeling it's too bland, find the battles lacking and just don't like the overall tone of this one. Feeling it lacks the quirky charm of the 90s version.
While a great number of fans of the manga and/or the first anime would like to forget this series exists at all and prefer to just stick to the earlier adaptations, some only ignore the first arc, finding the series from the Black Moon arc onwards to be of a more watchable quality than the Dark Kingdom arc. The fact that the latter has previously received an expanded adaptation in the form of the live-action Pretty Guardian Sailor Moon series (and has been recycled to death in the musicals) probably contributed to this to an extent.
The release of Season 3 pushed this further, with many people choosing to ignore the previous episodes (although there's a small group that ignores Season 3 due to the art style change and recycled stock animation).
Growing the Beard: The reception to Season 3 was much more positive, and a number of fans have stated that the show took a general upturn in quality around that time.
There's a fair number of people who feel that a Shot-for-Shot Remake of a manga they'd already read, covering the same territory as the live action series and the first season of the old anime wasn't what they got excited for when they first heard Sailor Moon was coming back. Many fans who were interested in a Truer to the Text adaptation, meanwhile, express disappointment at how faithfully Crystal replicates the manga's flaws - such as its rushed pacing, lack of characterization for everyone outside the main cast (and even the main cast itself in the first arc), and plot holes - rather than taking the opportunity to improve upon the manga's weaknesses.
Choreography and poses from the first anime's Transformation Sequences and In the Name of the Moon speeches were repurposed for Crystal. While many fans feel this is a nice nod to the original, others were expecting more creative, entirely new transformations and choreography.
Sailor Moon's Moon Prism Transformation being almost exactly the same as her Moon Crystal transformation except for the brooch being different. There are a few that are OK with this, but most have loudly complained about SMC's apparent laziness, especially people who hoped that at least in Crystal, the upgrades meant a different Transformation Sequence also for the other Inners, not just Sailor Moon.
Season III got hit with accusations of reusing key animation from the previous anime's attack sequences and a general overuse of Stock Footage (compared to previous seasons, where a lot of attacks were shown in real time).
The franchise always had a big one anyways, but older LGBT girl fans (who loved the manga and got upset at the 90s dub, as the reputation goes) are vibrating excitedly at how nicely Usagi's attraction to almost every girl she sees is being treated on the screen.
With the introduction of Haruka and Michiru, fans have been going nuts, especially since this version is far from coy about the fact that the two are in a romantic relationship (in contrast to the infamous Bowdlerization attempted by the original English dub of the '90s anime).
Most transgender and non-binary fans have been squeeing over Haruka, as most identify Haruka as genderfluid, thanks to this page◊ from the manga and this scene◊ from season three.
Every time Usagi sees a pretty girl or meets a new main character, she acts like she just fell in love. Of course she does this with guys too, just not as much.
Usagi calls Ami really cute several times in Act 2 of the manga, while in Act 2 of Crystal there's a bit of Luminescent Blush as she does it, with Ami also blushing profusely when Usagi effusively hugs her, and again shortly after, when Usagi tells her that she's cuter when she smiles, while obliviously using the -chan honorific.
In "Sailor Mars", Ami uses "you can see a beautiful girl" as an incentive to get Usagi to come with her to the cram school. Usagi's naturally excited, and when she actually sees Rei, gets hearts in her eyes. Ami tells her it's rude to stare. And then when Rei gets off the bus, Usagi does too just so that she can follow her.
"Sailor Jupiter" starts off with Makoto saving Usagi, and after she walks off, Usagi's in love again and muses that the other girl smelled really good.
Chibi-Usa musing about how beautiful and pale Hotaru's skin is. Usagi agrees with a knowing expression.
Hell, the entire 3rd season has lesbian undertones all over it. The opening sequence shows both Chibi-Usa and Hotaru naked around a bed of flower petals, and there's an entire ending dedicated to Haruka and Michiru's relationship using the same imagery.
In Act 36, Hotaru tells Chibi-Usa she loves her right before dying. This didn't happen in the manga.
In Act 28, Minako's gift to Rei for her birthday is Casablanca Lilies, the same flowers Rei always got from her first love. Minako also says she brought them because she knew how important they are for her.
Mis-blamed: Many of the specific scenes and plot elements that Crystal's more vocal critics use as examples of how the series is "ruining" Sailor Moon, such as Usagi's attempted suicide at the end of Act 12, existed in the original manga and were simply reproduced in the adaptation.
The Pocket Protector twist with Mamoru's moon phase pocket watch and the Shitennou stones, which didn't make any more sense even in the manga itself, especially with the latter actually showing a lot of blood; Crystal worsened it somewhat through an Adaptation-Induced Plot Hole regarding the stones, but it still was something taken directly from the source material.
Some of the complaints about Act 13 included the fact that it ends right as Sailor Moon prepares to unleash the final attack on Metalia, making it look like the final battle was split into two episodes for padding purposes. The corresponding chapter of the manga ends on the same cliffhanger in all editions.
A common complaint about Crystal revolves around the story's close focus on Usagi and her relationship with Mamoru, while the rest of the Sailor Guardians, particularly Mercury, Mars, and Jupiter, have very little prominence or development after their introductory episodes. Since the '90s anime uses its much longer running time and monster-of-the-week format to give equal attention to all of the team members, the contrast is understandably jarring, but this too comes directly from the manga, which doesn't really begin fleshing out the ensemble until later story arcs.
Kunzite having fair skin consistent with his manga design, as opposed to the darker tan skin tone he has in the '90s anime, has led to accusations of whitewashing. This accusations of whitewashing have also been applied to Nephrite, due to his skin tone being somewhat paler than it appeared in the original anime, although the difference is not as significant as with Kunzite.
On the other hand, long-term fans of the manga sometimes blame Crystal for "errors" that were, in fact, changes introduced in the later manga editions (Crystal being specifically based on these reprints, down to the episode count and naming). One such example is Sailor Moon retaining her choker accessory in the form of her first transformation brooch even after getting her second transformation.
While Crystal had altered the Shitennou's fates to an extent, the deaths of the Spectre Sisters in the Black Moon arc and their treatment as monsters-of-the-week is consistent to their role in the manga.
Kunzite and Zoisite not being portrayed as a couple added a great deal to the already heated debate regarding the Senshi/Shitennou pairings, and caused some to outright accuse Crystal's creators of censorship and homophobia. Kunzite and Zoisite's relationship was a subplot exclusive to the old anime series, and was never present in the manga; Takeuchi's notes indicate that the two of them were meant to be more like brothers.
Moral Event Horizon: Metalia manages to get an extra one hammering in villainy when the Sailor Senshi free the Shitennou from her mind control, she kills them saying that if they reject the darkness, they're useless.
The frequency of Off-Model animation can seriously throw off the mood, especially at the beginning. It doesn't help if the episode first has some gorgeous animation, like the reveal of Princess Serenity... and then follows up with Off-Model scenes. Oops? Case in point, Chibiusa's◊ transformation◊.
The Nico Nico Douga subtitles (which use the same script on CrunchyRoll and Hulu) use some drama-breaking translation choices. For example, in Act 3 Jadeite's cry of "Onore!" as he's engulfed in flames is translated as "Rascal!"
In episode 6 of season 3, when the girls find Tellu's victims, the official subtitles put Rei's line as the very meme-worthy, "Look, everyone goes down!"
The subtitles for Act 33 cause a lot of inappropriate snickering by using the word "aroused" instead of "awakened" when discussing Sailor Moon's powerup to Super Sailor Moon and the prospect of Sailor Saturn awakening as a senshi.
The show's tendency to employ Bloodless Carnage, contrasting the original manga's High-Pressure Blood, took a little bit of seriousness out of the scene where Sailor Moon kills the possessed Mamoru by slashing him across the chest with a sword.
QueenMetalia, thanks to her design being much more faithful to the manga. Sure, we don't get the Nightmare Face from the manga, but having nightmares about the Big Bad killing the love of your life is still horrifying.
Ship-to-Ship Combat: The survival of the Shitennou and their increased presence in the plot has revived the once very ugly debate regarding the scrapped subplot about the Shitennou and the Inner Senshi having romantic links and turned it Up to Eleven. Episode 10 had confirmed past romances between the Senshi and the Shitennou. A lot of the fandom weren't pleased. Episode 12 continued the revelation, but also killed off the Shitennou and had all four Senshi cry over them, which only worsened the rage.
For many fans, when Black Lady kisses a hypnotized Mamoru. TWICE. (This happened in the original manga, too, but even among those familiar with it few people expected these shots to be kept in.)
Some fans found Usagi and Mamoru's ambiguous love scene and following Sexy Discretion Shot in Act 19 gross for many reasons, including the fact they're both minors note Usagi is fourteen/an 8th grader and Mamoru is seventeen/an 11th grader.
They Changed It, Now It Sucks!: Nostalgia for the original anime drives many of the complaints, especially amongst people unfamiliar with the manga and even more so among English speaking fans whose familiarity with the franchise comes from the DiC dub. On the flip side, for some vocal fans of the manga, any divergence from its text is a point of contention. Specific items of complaint range from the inclusion of confirmation that the Senshi and Shitennou were romantically involved in their past lives to minor details like the absence of certain jokes and gags.
Some people feel the story arcs have rushed pacing, which once again is a byproduct of faithfulness to the manga.
Episode 7 changed Tuxedo Mask's participation in Sailor Moon's confrontation with Zoisite from not being able to reach her at all to an actual attempt at defending her, which served to emphasize his switch from just wanting to obtain the Silver Crystal to desperately wanting to protect Sailor Moon herself. Cries of the theme song being defied followed.note For justice's sake, let's point out that Tux rather quickly loses against Zoisite, clearly showing that he is completely powerless. Not to mention that, in the original manga, the Senshi themselves were losing to him as well until Sailor V pulled a Big Damn Heroes moment, and Crystal simply inherited that scene. Additionally, in the manga it was still ambiguous just where Mamoru's loyalties really lie at this point, which made his Heroic Sacrifice in the next chapter a sort of a last-moment life-changing decision (whereas Crystal has him more or less confessing his love for Usagi already).
Episode 8 altering the plot so that Minako insisted on fighting Kunzite alone has split fans more, with complaints that getting rid of the girls' group bonding scene to have Minako want to go at things alone flies in the face of the series' messages about girl power and friendship. On the other hand, other fans love that Minako got a unique characterization than the other Senshi that show how burdened Minako is by her status as leader of the Senshi, and note that it results in a different but equally powerful team bonding scene when the rest of the Senshi catch up to her and insist that she doesn't have to go it alone any more.
Episode 12 did another plot alteration by having Beryl killed by Sailor Moon instead of Sailor Venus, which some fans saw as downgrading Minako's power as the leader of the Guardians (Venus is instead the one to cut the Senshi free of Beryl's Prehensile Hair, an act performed by Sailor Jupiter in the manga, but this change is rarely criticized). It doesn't help that the scene was Bowdlerized so that instead of impaling Beryl with the Holy Sword Sailor Moon simply destroyed her necklace which was linking her to Metalia's powers (a detail that never existed in the manga).
The show's tendency to focus on romance in general, be it Usagi/Mamoru or Senshi/Shitennou. While some argue that the romance in the manga was already idealized to begin with, others find the expanded version cheesy and unnatural, or are only willing to accept the changes as long as they don't get close to the Adaptation-Induced Plot Hole territory, which happens on some occasions. Specific examples:
The scene with Usagi and Mamoru inadvertently ending up together on a bus in Act.3, which in this version leads to Usagi getting embarrassed and hilariously trying to cover her blushing face with Luna. In the manga, Mamoru explicitly recognizes her as Sailor Moon and, from her conversation with Luna, starts to suspect she is somehow connected to the Silver Crystal, which serves as an additional explanation of him following Usagi as Tuxedo Mask when she leaves the Hikawa Shrine to investigate the cursed bus (Crystal did leave in a similar scene in Act.2, though).
The Shitennou stones. Due to Crystal expanding the Senshi/Shitennou subplot, the four villains were left alive until the final confrontation with the Dark Kingdom, only to be abruptly killed off by Metalia just as the Senshi managed to undo her brainwashing on them, for drama's sake. The problem being that, in the manga, Mamoru carrying around the stones the Shitennou turned into was crucial to the plot, because they ultimately acted as a Pocket Protector when Sailor Moon slashed him with a sword (which still happens in Crystal but with no explanation). As a side effect, people not familiar with the manga were puzzled by the scene where the Shitennou appear before Mamoru as his Spirit Advisors.
The removal of the subplot in Act 13 involving Mamoru temporarily going blind as a result of Metalia's powers possessing his body (though it was already hinted at when the animators went with Red Eyes, Take Warning for him, instead of the manga's black) for the sake of achieving the happy ending for Endymion and Serenity an episode earlier. The complaint being that, in the manga, not only is it what leads to him effectively discovering/remembering his ability to observe the Earth just by touching the ground, but also strengthens the True Love's Kiss scene, which simultaneously revives Usagi and cures his blindness.
Fan response to the new art style and 2D transformation sequences introduced in Season 3 seems to be mostly positive, but there is a camp of fans protesting that they preferred how it was done in the first two seasons.
As Michiru and Haruka are known as a power couple thanks to the 1990s anime, many fans were horrified to see Haruka kiss Usagi (more than once at that). Even though the scenes are from the manga, many were annoyed by the infidelity their Ship Tease causes.
Unintentionally Unsympathetic: Prince Demande is given a sympathetic death that wasn't in the manga, which doesn't really add up when you consider that he is an attempted rapist and all-around horrible person, and that he had literally just attempted to destroy the universe before this death happens.
Win Back the Crowd: Season 3 saw a number of changes to the show as it moved from a web series to airing on television (and presumably gained an increased budget in the process). Most notably, the art style was changed and the transformation sequences done away with in what may well be a purposeful attempt at addressing fan dissatisfaction with those elements.
The Woobie: It's hard to not want to give Sailor Moon a hug after the first episode. While she did dream about "beating up bad guys," she gets a massive dose of Reality Ensues when she finds her life in mortal danger and she has no clue what the heck she's doing! Fortunately, after a few battles and more experience, she begins to break out of that mold.