Anticlimax Boss: Dai Gurren rams into Cytomander's Shuzack and sends him crashing into his own battleship, incinerating him in the colossal explosion. In the movie, he can't even get an attack off before Simon mulches him with a Giga Drill Break. It just goes to show how low he really is—he's not even good enough to be killed ceremoniously.
People either hate Rossiu for using Simon as a scapegoat for the Anti-Spiral attacks post-Time Skip, or forgive him and see it as an integral part of his character arc.
The Anti-Spiral is one, albeit it's not so much half the fanbase hates it while the other half likes it. The matter is more if its actions can be excused as a Well-Intentioned Extremist, or if it has crossed the line.
Nia: Is she a compelling character and good foil to Kamina, or is she an unnecessary Satellite Love Interest to Simon? As mentioned below, was her death completely contradictory to the idealism of the series, or was it necessary to show how much Simon matured?
Yoko has gained a notable Vocal Minority, calling her out for being unnecessary fanservice and adding nothing to the series. Most people tend to see her as a competent Action Girl with a good deal of Character Development of her own.
Dueling Works: Oddly, with Yes! Pretty Cure 5 - Gainax got a strongly worded letter from Toei when a manga was posted with one scene depicting Yoko shooting Weasel Mascot Coco. Apparently, magical girls were a threat to the high-octane action this anime became.
Epileptic Trees: One popular theory is that the world of Gurren Lagann is what happened to Earth after the end of Neon Genesis Evangelion. Considering it's revealed that the Angels generate their power from helical DNA, and humanity itself is the 18th Angel, this is getting dangerously close to being plausible.
Esoteric Happy Ending: Yes, the universe was saved and the Anti-Spiral didn't kill off humanity, but many of the crew dies (including Kittan, right after he confesses his love for Yoko), Nia dies just after her and Simon's wedding and Simon himself becomes a hobo of sorts, which comes off as a rather insulting fate for someone who saved the entire man race from extinction. Not to mention, the Spiral Nemesis, the thing the Anti-Spiral were trying to stop from happening is still a potential risk that has a very real chance of transpiring and destroying everything. For such an idealistic series, the ending can be especially jarring.
"Funny Aneurysm" Moment: One Parallel Works video features Viral with a Beastmen daughter and wife, and he realizes that it was All Just a Dream after seeing Kamina in them, so he decides to find a way to stay awake so he doesn't have to dream anymore. Come episode 26, and it's revealed that all Viral wants is a Beastmen daughter and wife (who are the same ones in the Parallel works), and he comes to realize that it's All Just a Dream when Kamina saves everyone from the Interdimensional Labyrinth, calling the whole act sappy. And unlike last time, it's notPlayed for Laughs.
Genius Bonus: The Four Generals' names are based on the names of the four bases in DNA. Thymilph: thymine; Adiane: adenine; Guame: guanine; Cytomander: cytosine. Especially good when you remember that A and T are complementary base pairs. They also take inspiration from how the four classical alchemical are represented by specific creatures: Gnomes (Earth), sylphs (Air), undines (Water) and salamanders (Fire). Guame = guanine + gnome, Thymilph = thymine + sylph, Adiane = adenine + undine, Cytomander = cytosine + salamander. (Air and Fire have clearly been swapped here, though.)
Many of the off-hand comments to the effect that Kamina is gonna get himself killed in the early episodes. Viral's warning "your bravado will get you killed" and Kamina's own "I'd be dead if it wasn't for your level head" to Simon in episode three come across as Foreshadowing once you get to episode eight.
In Episode Seven, Rossiu warns everyone that "Good intentions can sometimes tempt good people into traveling down the wrong path." Post-Time skip, he's doing exactly what he was warning against. He even mentions the effect it had on his village, which is what Simon compared it to when he found out.
The finale of Lagann-Hen and TV series becomes this when you remember in episode 4, Kamina said that more than 16 combinations sound "Stupid", when in the movie that's almost exactly what Simon and the Dai-Gurren do near the end of the battle, to turn into a giant energy Kamina. Of course, the reason why Kamina said it was stupid was that more faces doesn't make you powerful, it's the bond between the spirits combining that gives you power. Take a look at Team Dai-Gurren's close friendship.
He's Just Hiding: Within the fandom, Kamina has loads of fans who refuse to accept that he was killed.
Nia gets this a lot too, with people insisting there's always hope for her return.
Hype Backlash: Thanks to a...VERY enthusiastic fanbase, certain watchers don't believe the series warranted the hype it got.
I Am Not Shazam: You may see many references to "Lord Genome" which are technically incorrect. Officially, "Lord" and "Genome" are not his title and name, rather "Lordgenome": one word. is just his name. Thus it is pronounced as one word in both the Japanese and English versions. This hasn't stopped a few fans from hilariously back-mistranslating it as "Genome-sama".
It Was His Sled: Chronologically: Kamina dies. Also, there are things called "Anti-Spirals", and the final incarnation of Gurren Lagann is big enough to throw galaxies like shuriken. That second one is the most common, followed by the third. Even on this very wiki.
Kamina, or rather his sunglasses. There's even an Emoticon for them! ◥▶◀◤
Simon. He invented teleportation specifically to punch someone in the face. Unfortunately, they got rid of the teleportation part in Lagann-hen and all we get is Kinon slapping Rossiu's face. Still awesome but not as awesome as the one from the TV series.
Memetic Loser: Simon. While early-series Simon is trying to find his footing and hence is not as Crazy Awesome as Kamina, late in the series he surpasses his "Aniki" in spades and Kamina himself acknowledges it (if posthumously). Alas, the meme guys didn't get the memo and Simon pretty much remains a useless whiny little bitch in their eyes, and if they do acknowledge his late-show achievements, they get rather schizophrenic about it: Simon's not one guy who outgrew his problems and faced his fears and became a Badass—it's more like there's two men called 'Simon', one who is a whiny little bitch and one who is pure high-octane GAR with no in-betweens.
And many other things that the Anti-Spiral does in the series. The only possible excuse is being both a Well-Intentioned Extremistand utterly insane.
Depending on who you ask, Rossiu crosses this at some point during the post time-skip era (exactly when is open to significant interpretation). Some of the fanbase were not happy when Simon prevented his suicide.
From the dub, episode 11: "ROSSIU! Let's COMBINE!" The following Crowning Moment of Awesome is made even better by Yuri Lowenthal's delivery and the new script, though, so it's all good.
How does Gurren Lagann make that "sproing" sound effect when it moves appear so awesome?
The whole show pretty much runs on it. The story is pretty poorly constructed for the most part, especially its extreme overuse of Deus ex Machina, but the creators' sheer love and enthusiasm for their work drips from every frame and makes it beautiful.
With the way it's spoken about online you'd think that it invented mecha.
Spiral Energy at first seems like a concept original to this show, but in actuality it was originally a concept from Neon Genesis Evangelion. The "Classified Information" files in the game Neon Genesis Evangelion 2 (released in 2003) reveal that the Angels' S2 engines generate an inexhaustible form of energy from, you guessed it, helical energy derived from their DNA-like shape. Beyond even that, the concept of Spiral Energy as depicted in the Gurren Lagann is as old as the super-robot genre itself. The idea that the robot suddenly became stronger because the pilot/controller is all fired up is one of the defining tropes of the genre, after all. Gurren Lagann just gives it a name and a gauge rather than playing it off as just something that happens in these sorts of shows. Also, the plot about the heroes' reality-bending power dooming the universe with eventual overuse was almost directly lifted from a Getter Robo story: Spiral Energy is Getter Rays and the Tengen Toppa Gurren Lagann is the Getter Emperor.
Spiritual Licensee: Especially in the second season, Tengen Toppa Gurren Lagann basically comes off as an adaptation of the later arcs of the Getter Robo saga, with Spiral Energy becoming an even more obvious parallel of Getter Rays and there even being a Getter Emperor equivalent.
Some fans feel this way about Kamina, feeling that he would've made a more interesting protagonist than Simon.
Kiyal, one of the only female characters that pilots a mecha, gets sidelined and dropped Out of Focus after the timeskip, with her mecha combined into Kittan's, wasting an opportunity for her to join the rest of Dai-Gurren, as well as plenty of character development and story potential.
Nia had potential to be an interesting character, but gets sidelined to being Simon's perfect girlfriend and the go-to Damsel in Distress. Made even more blatant in the movie remake, where she racks up more DID points (her rape at the hands of the Anti-Spiral is probably the most prominent example) and, though she gets an opportunity to kick ass with her mecha Solvernia, ends up basically doing nothing of worth and getting beaten down despite all the potential for her to fight against her creators.
The Spiral Boy manga, set in an alternate universe. Simon meets Nia early, Yoko and Kittan are agent hunting down gunmen users (though Yoko eventually does a Heel–Face Turn), Kamina is the leader of a bunch of rebels with Viral of all people, the whole group are outlaws against a grown Rossiu and Lordgenome. Unfortunately, it was canceled after five chapters.
There was an opportunity for Rossiu to fully redeem himself and prove his skills as an effective and valuable leader of the populace by encouraging them to use their spiral power to help Team Dai-Gurren versus the Anti-Spiral. Instead, we get nothing of the sort, and in the epilogue, praise of Rossiu's leader skills from Leeron that comes off as empty and meaningless due to the lack of development backing it up.
Kamina has this a number times, such revealing himself to a Gunmen when Yoko is trying snipe or walking into a hotspring that obvious a trap.
Kittan had a magnificent display of this in episode 11 when he fell for the most obvious trap because he thought he was actually going to rescue a bunch of women supposedly under attack by gunmen.
The Anti-Spiral makes it pretty clear its victory in the past didn't come from outthinking its enemies, considering it keeps wanting to push the protagonists over the Despair Event Horizon, and never seems to take it hint that doing that doesn't work and keeps giving them chances to become more powerful to the point where they can actually win.
The Woobie: Poor Viral can't catch a break, even in his dreams. All the poor guy wants is a family, but being a Beastman he can never reproduce, and after Lordgenome makes him immortal he'll outlive any family he could possibly have.
And Nia gets it even WORSE. She has to will herself to stay alive just to make it to her wedding, which happens right after she's kidnapped and raped.
Simon arguably gets it worst of all, what with losing his parents, his best friend who was also his surrogate brother and something of a father figure, and a good chunk of his friends from Team Gurren. Along with that, he was betrayed and then character assassinated by his close friend and Well-Intentioned Extremist Rossiu, who also had him condemned to death. And to top it all off, his lover, who rescued him from a deep depression after losing aforementioned surrogate brother, and for who he literally tore apart the universe trying to save, crumbles into dust moments after they're married. Someone give this kid a hug, dammit.
Yoko after both the men who loved her die.
Kamina, who devotes his life to getting to the surface so he can meet his father and finds his skeleton on his second night there. It gets even worse when you find out that his over-the-top personality is all a fake and he is as scared as the rest of the Brigade, if not more.
Woolseyism: In the Japanese version, Kamina's last words roughly translate to "Farewell, comrades." The dub sets it to "Later, buddy..." which is arguably more powerful and fits his character better.