Funniest fandoms are where the fans are like, "I'm obsessed with this. I don't recommend it even slightly."
I am horny about Aquarion
I like Aquarion for the mecha but also because there's a slightly chubby (by anime standards) girl whose character arc consists of understanding she's most powerful not when she syncs her orgasms with her partners but when gets off so hard it unlocks more powerful mecha moves.
Aquarion is the Horniest Mecha Anime
And that is saying a LOT. Between Gurren Lagann's drill which is your soul (but sometimes your penis), Darling in the FranXX's mecha which can only be piloted doggy style, and countless shows where those two angry boys clearly just want to kiss but they have to fight with robots instead, mecha is a supremely horny genre of anime. Genesis of Aquarion looked at all that and decided no, subtext is for cowards. In our show, merging mecha is pretty much just sex. Also, we only do threesomes here.
Yes, to be very clear, the way the titular mecha is formed is three pilots combine their fighters in a process that involves a lot of moaning. The pilot "on top" is in control with the others providing various amounts of support. Characters talk about their first times, about how it's just not the same in a simulator, about how it's different with different co-pilots... look, it's just sex.
But right, the show. In the sorta future, Earth is under attack from aliens that are also angels who are kidnapping people to eat/form the biomass of something evil they're building. Ya boy Apollo sees his buddies get literally pasted and falls into the cockpit of one of the parts of Aquarion, where he finds out he's psychic, he's pretty OK at flying, and it feels real good to "gattai" with him.
Great, now it's time for Evangelion only instead of depressing shit it's sex stuff, instead of daddy issues it's more sex stuff, and instead of Jesus stuff it's... actually, no keep the Jesus stuff. Are the people commanding the rowdy teenage mecha pilots maybe manipulating them a bit? Well yeah, this is a mecha show. They're child soldiers. At least the leadership mostly wants to build them up, not tear them down. Is there more than it seems to our protagonist and his link to the titular mecha and the antagonist? You betcha! Is anyone actually having sex? No, surprisingly.
Aquarion isn't just a mecha show, after all. It's also a show about a bunch of teenagers in a hormonal blender just figuring out how feelings work. By replacing actual sex with mecha stuff that's basically just sex, it gets to fully reckon with how important sex is, while not getting kicked off broadcast TV. This saves it from both the horny show trap of becoming essentially soft hentai and from disingenuously suggesting that no sir, those teenagers getting extremely hot and bothered with each other absolutely do not shack up because sex before marriage is wrong.
OK doubling back to the characters: there are a LOT of them. I only really like maybe half of them, but that's fine since there are so many options. I don't want to talk about all of them all day so instead I'll talk a bit about my favorite: Tsugumi Rosenmeier. Awkward, techie, and clearly trying her best - miss me with the conventionally attractive popular girls, this is my kind of character. She has a problem where she "goes off" too fast during gattai, which causes a power surge and performance problems. This is used for humor to some extent, but the show doesn't shy away from how being unable to sync up wth her peers makes her feel left out or like she's letting them down. Compared to the struggles of reincarnated fallen angels from 12,000 years ago, Tsugumi's problems are more grounded and relatable.
Time for the 88 ton mecha in the room. The back half of Aquarion becomes suddenly nigh-unwatchable due to filler and five consecutive budget dump episodes. Seriously, something must have gone horribly wrong because the plot mostly just stops for several episodes of filler stuff they clearly did not have the time or money to make. Character models are a suggestion at best. One episode they actually decided to make an artistic choice out of the whole mess and go for a simpler style, but even that struggles to maintain internal consistency. This is the single reason I can't recommend Aquarion - I simply think many people would not get through that roadblock, and I wouldn't blame them.
Conclusion
Score: 8/10. I really like Aquarion. It's very refreshing to watch something with no pretense. For a show so overtly about sex, it wastes a lot less of its time on actual sexy stuff than you would think. Instead the camera is on two things: sweet mecha action and a bunch of teenagers working through the emotional side of romance, with an emphasis on shenanigans.
Recommendation: Don't watch Aquarion. It pains me to say this, but the budget issues are so catastrophic that I can't in good conscience recommend it. There are also a few other issues. Despite everyone needing to be functionally bisexual, there is still some homophobia in the show itself (the first time an all-male gattai gets going it's called "unnatural"). Even before the budget ran out on there were episodes where the protagonists gain a new skill, use it once, and then don't reference it ever again. The CG has also not aged especially gracefully since the mid noughts.
Comparisons
Aquarion is deeply derivative of Evangelion, there's no question about that. The thing is, I don't actually like Evangelion. Depression may be relatable, but it's not fun. On top of that, I find the characters in Eva to be so relentlessly unpleasant to be around that I can't actually get enough into their heads to relate. Aquarion makes you feel like you're hanging out with your extremely horny friends, which is a lot more fun than hanging out in a psych ward. Dump episodes or no, I'd rather watch Aquarion ten more times than watch Evangelion once.
Shakugan no Shana is my favorite anime I don't recommend - yes, even though it's rated lower than Aquarion at a 7/10. When not in their respective problem parts, Aquarion is a better show in many ways. The reason why Shana comes out ahead is hard to articulate. Shana's biggest problem is tone whiplash. Aquarion's messy third quarter hits closer to the core of the show than Shana's issues in the first half of season three do, and it's more severe. On top of that, for all that I do like a good few of the characters in Aquarion, none of them stuck with me for as long as Shana's have.
Final Words
Aquarion is the only thing I currently rate as 8/10 that I can't recommend. The fact that it's at that level shows just how much I like the good stuff.