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.
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.
Although many view Rossiu as The Scrappy, he has a sizable contingent of fangirls that still love him.
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.
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 she and Simon have their first kiss 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.
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.
Which is fitting, considering they were created by LordGenome.
Maybe not so much a Genius Bonus as a Literary Scholar Bonus, but the other parts of their names count too. In a lot of older poetic works, and presumably also in Western esoteric traditions, the spirits corresponding to the four classical alchemical elements are 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.)
Harsher in Hindsight: 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.
Hilarious in Hindsight: Volfogg is played by the same voice actor as Kamina. Volfogg essentially does that in GaoGaiGarin the final episode.. So Kamina's a hypocrite?
Hype Backlash: Thanks to a...VERY enthusiastic fanbase, certain watchers don't believe the series warrented 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 got 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.
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 TTGL is the Getter Emperor.
Rescued from the Scrappy Heap: Not that the minor characters from Team Gurren were Scrappies, see, it's just that no one really cared about them. But then episode 24 hits, where all of them go out in one heck of a blaze of glory. Manly Tears were shed.
Simon himself counts to some fans. He started out as essentially a whiny Shinjiclone who was indirectly responsible for Kamina's death (despite showing more tact than his brother and openly said to be the reason of their success). However, after some well-played Character Development and an epic He's Back scene, he proved himself as a courageous and likable character. And then he gets really awesome after the timeskip...
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.
What an Idiot: 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. 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.
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.