Gen Urobuchi has stated unequivocally that he had nothing to do with the ending of Aldnoah Zero. Washed his hands of it. So done. Once you see it, it’s easy enough to see why: divisive, to the point where it overshadows the rest of the series that, when all’s said and done, is entertaining but shallow.
imprisoned by gunmetal grey military vessels and featureless wastelands
It treads in familiar footsteps with its concept: mankind divided, the Earth threatened, a war fomented. A force with vastly superior technology attacks an unprepared populace, oh the humanity. This isn’t anything that you haven’t already seen before in numerous other mecha shows and, depending on the breadth of your experience with that genre, done better.
Rewatching Code Geass R2 set my mind working on something that has been gnawing at me for a while, and it's only recently that the semblance of an answer began to take form. The part in question takes place towards the end of the season and is when the Emperor's plan is revealed to Lelouch concerning the Mental Elevator, C's world and the Sword of Akasha: that of unifying the world into a single, super consciousness. Depending upon the anime one has watched this will likely be a familiar concept and one that has underpinned many influential and subversive series.
everybody ends up all warm and fuzzy and with a greater understanding of Mayan philosophy
The most obvious proponent of this concept is of course Evangelion which constructed elaborate systems based upon Jungian psychology, theology and science and implying that the next evolution of humanity isn't as discrete individuals but as an amalgam. Without delving too deeply into the labyrinthine plot of the series and movies, End of Evangelion demonstrates this with everyone melting into a fluid, whereas the final episodes of the series give a fractured glimpse at the emotional montage Shinji suffers during this. Released in 1995-96, this was mostly the result of Hideaki Anno who it is anecdotally said spiralled into neuroses around the half-way point of the series which is coincidentally when it shed all pretences of being a fluffy children's show and went full bore for dark and symbolic.
What started as an unholy union between Sunrise and CLAMP quickly became one of the most watched and talked about series on its release in 2007: Code Geass. Measuring its popularity would be impossible, but interest is still high even after a two season television run, numerous manga adaptations and other merchandising paraphernalia with a recent cryptic post on the official website rippling across innumerable blogs and outlets, reported as news.
The extra budget galvanised the already spindly CLAMP characters by subtracting clothes and adding cup sizes
Code Geass succeeded in bridging many different genres garnering it a wide audience: at times it slipped into bipedal mechanised combat, others a tortured love story. The main narrative drive however is the story of a minority facing a majority, the oppressed revolting against their oppressors; it gives the story sharp pathos and universal appeal. It also doesn't hurt that the series is completely crackers, continually attempting to one-up itself resulting in rapidly escalating insanity. What was once a brilliant tactical manoeuvre becomes de rigueur and the increasingly ridiculous situations require similarly absurd solutions. Called a trainwreck by many, the series managed an ending that was supremely satisfying and tied up enough loose ends to provide closure to all but the most ardent fans.