Alternate Character Interpretation: What was Char's real motivation for all of this? It's generally accepted that he started the entire war so he could have his final battle with Amuro, but the Zeta Gundam game for the Playstation suggests that he honestly wanted to destroy humanity. His ending in said game shows him getting very angry when he senses Kamille getting Mind Raped by Scirocco, and then showing him in his CCA-era uniform and looking particularly unhappy. When you recall Char's attitude that it would be up to Kamille's generation to correct the mistakes of his own and create a new era, the ending serves to imply that he thought humanity was doomed to repeat the mistakes of the past and would never evolve past their petty conflicts.
Badass Decay: Char is often accused as this, as despite this movie hyping him and his final showdown with Amuro up the actual battle is a totalCurb-Stomp Battle in Amuro's favor. Of course, Char all but handed the victory to Amuro by breaking his back making sure Amuro had the best possible technology and suit with which to fight him, but it's still jarring how quickly and easily he is defeated.
The titlar Char himself. Some either consider him the star of the movie or a horrible character due to his villain-like characterization. The fact that he uses the young Quess just makes it worse.
Quess is another, due to her being intentionally created to be a Hate Sink.
Broken Base: The Hi-Nu Gundam's designs. Some prefer Izubuchi's original bulkier design which served as the basis for the SD design for the Super Robot Wars games that popularized the suit to begin with, and for the Ver.Ka model kit release in 2014. Others prefer the 2006's slimmer redesign, present in all games featuring the mobile suit post SRW Alpha 3, animated incarnations, most model kits and the Manga of the novel.
Make of this what you will, but most of the new characters get CMOA moments in later adaptations. Hathaway is allowed to mature and become a heroic character in the manga Hathaway's Flash (before being killed off in one of the darkest endings in Gundam history), Quess is allowed to pull a Heel–Face Turn in Gundam EVOLVE #5 (which may or may not retcon her and Hathaway's fates), and in perhaps the most amusing example, Shin Gihren's Greed for the PSP gives Gyunei the chance to actually pull off that Hostage Situationsuccessfully, capturing Amuro and the Nu Gundam while returning Kayra to the Ra Cailum alive. What makes this so amusing is that Char is utterly heartbroken by it, as Gyunei has essentially robbed him of his glorious final battle with Amuro.
"Main Title" and its variations played throughout the movie, such as "Segment III Sally" or "Aurora". This is Gundam, what did you expect?
And of course, the crowning credits' song: Beyond the Time, by TM Network. Thanks to the movie's trailers and the song being featured in games like the Super Robot Wars series, it became so emblematic of the movie that excerpts from its lyrics and even its very title would be worked into later adaptations and references to the movie, even of its novels.
Ensemble Darkhorse: Despite not even having been animated, the Hi-Nu Gundam is very popular amongst fans and directors - aside from the below mentioned expies it has, it was popular enough to receive it's own HG and MG kits, has appeared in several Super Robot Wars games, and even got to be animated in Model Suit Gunpla Builders Beginning G. Char's upgrade, the Nightingale, is similarly popular, if not quite to the degree of the Hi-Nu.
Fanon: Because Char's sub-commander/lover Nanai Miguel shares a surname with Usso Evin's mother, fans assume that Usso is Char's grand/great-grandson. This one was actually Jossed by Tomino himself as a coincidence.
The plan was originally for Uso to indeed be Char's descendant. But further into production, the writers decided against that and didn't want to lose all the work on character designs they'd accomplished.
The writers and Tomino had a conflict. The former believed Uso to be Char's descendant, the latter didn't.
Char, when he presides over his own Colony Drop of Fifth Luna. Welcome to the Gundam genocide club, Char!
Char again, when you examine his manipulations of Quess and Gyunei closely. Playing two emotionally-unstable and very powerful teenagers like violins just to further his own plans? One of them being a kid that he pretty much raised as a Tykebomb for at very least seven years? Yeah, that's gonna work well.
Gyunei, after the Hostage Situation that he came up with which ended in the death of Kayra Su.
Quess' defection and subsequent murder of her father was this, especially for people who didn't like her in the first place.
Hathaway's murder of Chan is one of these for others.
Narm: Because the Greek letter "nu" resembles the English letter "v", when written out, "Hi-Nu" looks like "Hi-v", which is one hell of a weird thing to find plastered on a model kit...
Replacement Scrappy: Although she's not exactly hated, Chan isn't seen in a favorable light by some due to replacing Beltorchika as Amuro's love interest - the latter would have appeared in her place, but Tomino wasn't allowed to use her VA.
Romantic Plot Tumor: Many fans view the Quess subplot and quadrangle between her, Char, Hathaway and Gyunei to be this, as it makes all the characters involved look worse. Hathaway and Gyunei go from relatively likable kids to murderous Crazy Jealous Guy types, Char himself is reduced to grooming a 13-year old child to be his weapon, and even ancillary characters like Nanai and Amuro get begrudgingly dragged into the drama. It's only natural for a child like Quess to think It's All About Me, but when the narrative itself makes the plot revolve around her, that's another thing entirely.
This might be a form of meta Fridge Brilliance given that Tomino's Gundam works in particular often have a sort of strong but thinly veiled Nazi analogue in the villainous faction of each story. One of Hitler's most dangerous traits is generally regarded to have been his strength as a masterfully manipulative orator... a trait which it would seem Char shares, both in and out of universe, especially as in-universe those who are loyal to him tend to be reallyabsurdlyloyal.
Rescued being a somewhat polite way of putting it, since the novel killed him off.
It took an actual retcon by Tomino himself in Gundam Evolve to rescue these two. Still, since the series is not as known as the movie they could remain as that.
Even Gyunei gets this to a degree, as the fan theory that he was supposed to be Kamille is endlessly bandied about in fan circles despite the evidence being no more than "Kamille should have been at Char's side, not this new guy!" This essentially turns poor Gyunei into a Replacement Scrappy for Kamille.
A very thin example, as while the Neo Zeon soldiers have been using funnels for almost decade, what they haven't been using are the brand new fin funnels. Gyunei makes it clear he has no idea what they are when he calls them radiator plates. On the other hand, Amuro does have a reputation for being a tricky combatant, so Gyunei's assumption that Amuro was tryong to pull a fast one isn't as far-fetched as it might sound.