These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ensemble Darkhorse: Noah, the cute Team Pet, is seen as a bro to most of the community, especially due to his never changing expression and his actions, like freeing Ao from capture in Episode 3. Most fans have compared him to Gulliver from the first series.
The random Okinawan man who takes Ao around in Episode 4 is also seen as a true bro.
Fan Nickname: Pied Piper's leader, Ivica, is now being called Stan Lee due to his similarities to the famous comic book creator.
Naru is often called NTRu due to her partnering up with Truth and becoming one of the antagonists.
Fanon: Many fans have come up with epilogues (such as the "delusions" threads in /a/ of 4chan) that diverge from the main plot at various points, including one where Ao arrives in a future where everybody still remembers him, Everybody Lives (including Ao's sister), and Ao hooks up with Fleur.
Genius Bonus: The lightning-generating Secret in Episode 8 was last spotted in Philadelphia in 1752, the same year Franklin conducted his famous "catch lightning with a kite" test.
Growing the Beard: Episode 12 seemed to be this while the series was airing; it looked like the show was taking a bold new direction that would bring it closer to the original series. The mixed reaction to many of the episodes that followed it indicate that whatever beard it had was quickly shaved off.
Heartwarming Aneurysm Moment: The revelation that Eureka can bear human children was considered by many to be one of the more heartwarming moments of the original series and a confirmation that humans can co-exist with Coralians. And then the final episode aired, which revealed that the high amount of trapar in the original series' universe is fatal to Human-Coralian hybrids. This made the scene showing Renton and Eureka burying their infant daughter unbelievably worse.
Memetic Mutation: Dewey was right.source Due to several revelations and themes which only seem to reaffirm the antagonist from the original series' belief that Humanity and the scub coral really cannot co-exist.
A picture of Eureka and Renton crying next to an Easter Island head (due to hatred of how Ao's sister died) has also proven popular.
Narm: Happens more frequently as the series progressed. Few people agree just how much of it there was, but many agree that not only is Truth the biggest contributor to it, but he IS the Narm.
Paranoia Fuel: As was shown with Team Goldilocks, the Quartz Gun has the power to change history, but nobody other than Ao would ever be aware of the effects, meaning one of your closest friends may suddenly stop existing and you would never notice or vice versa.
Ship Tease: Now that Naru seems to have been taken out of the picture, there are quite number of subtle hints at an AoxFleur pairing.
The Scrappy: Truth is almost universally disliked among fans, mainly due to being introduced completely out of the blue, having overpowered abilities including energy projection, flight, and shapeshifting in a series that has thus far avoided having such characters, messing with Ao's head, taking and manipulating Naru, and randomly slaughtering people.
Naru is quickly falling into this category as well, especially after her Face-Heel Turn when she joins Truth and becomes one of his collaborators.
Take That, Scrappy!: Episode 23 seems solely dedicated to this. Naru gets her comeuppance for all the crap she's pulled. It even turns the end of the previous episode on its ear just to make sure you have basically no sympathy for her. Truth, meanwhile, erases himself from existence.
The common fan reaction to the Red Herrings of TheEND and Elena. Especially the latter, due to all the build up, and hints that she was Ao's sister. It smacks of Writer Cop Out.
Strawman Has a Point: The series proved that Dewey Novak was right about humans and Scub Coral being incapable of coexisting, seeing as how it was the Scub Corals' fault humanity was getting screwed over.
They Just Didn't Care: Many fans felt this way about the the direction the series took, pointing out how the themes stressed in AO were wildly different if not outright contradictory with the themes set forth in the first series.
They Wasted a Perfectly Good Plot: Many potentially good plot points such as whether Elena was from the original E7 universe or not, the presence of theEND, the identity and fate of Ao's sister, and many more were either ignored or turned out to be Red Herrings. In fact, you could say that they Wasted a Perfectly Good Sequel.
Win the Crowd: Certain aspects of the manga were not well received by the fandom. The anime, on the other hand, starts off with two episodes that gleefully lampshade and subvert many of the tropes of the original series, as well as having the main character one-shot a giant monster with his own mech's severed arm. The anime has been much better received so far.
Episode 12 has won the approval of a lot of fans who were becoming tired of the sequel's direction.
Episode 19 is considered one of the best episodes.
Episode 22 was rather well-received, mostly because Renton finally shows up.
As indicated by the tropes on this page, none of these examples lasted; the series as a whole is considered a Contested Sequelat best.