(MAL LINK)
To give credit where it’s due, Aldnoah.Zero did have a nice final scene in the first episode. It was a good way to set the tone for the series, even though the tone wasn’t entirely convincing. The tone wasn’t the worst thing about the show, though. Actually, I can’t tell what the worst thing about the show was, because it felt like such a total train wreck to me. The main character’s stoicism quickly got so extreme that it was impossible for me to relate to him. The conflict between worlds was interesting as a premise, but the character writing on the side of the Martians was absurdly obviously meant to make them look like the villains, which undermined any ideas of moral ambiguity. Ok, ok, but “what if it wasn’t about moral ambiguity?”, you ask. What if it was an underdog story? Well, in that case, it took all of, what, 3 episodes to establish that the main character was going to be able to defeat anyone in single combat. Which he eventually effectively did.
And then there were the CG mechs. Now, I’m not a person who has something against CG in principle. I understand and accept the usage of CG to animate mechs nowadays. The first mecha series I watched was Suisei no Gargantia, which had CG mechs, and I was fine with that. But, Gargantia also taught me that mecha series are usually about more than just the giant robots. And that’s where I think Aldnoah.Zero failed the hardest. It focused way too much on its awful-looking robots(also, boring designs), and I just couldn’t care about it. The only character I cared about was one of the Martian soldiers in the final episode of the first season. He was shot to death like a minute after he was introduced, but what he said felt genuine. He didn’t care about the CG mechs, he cared about the world itself. I wish all the characters had been like that random soldier guy.
Ok, I’m nitpicking and exaggerating a little, but I stand by my main points. I felt like the writing was really one-sided and way too focused on the bad-looking mechs. It felt like it was written by someone who thought the Gundam was the most interesting thing about Gundam 0079. I never even bothered to watch past the first episode of Aldnoah.Zero Season 2.
Falconhaxx 
Saw the whole series. It is without a trainwreck, basically a modern Code Geass without enough episodes to get itself together. I do think that the best part of the show was the tactics behind the season 1 battles, though. That kinda got tossed out the window, also like Code Geass, but it isn’t an anime that I truly hate. That would… probably be G no Reconquista or Build Fighters Try. Those were atrocious.
Oh, good point about the tactics. I liked the physics-based explanation behind the first enemy who could phase out. The solution there was pretty cool.
Unfortunately, yeah, the explanations after that got lazier and lazier.
I thought the conclusion of Aldnoah.Zero seemed either rushed, half-assed, or both. At the end the Vers Empire is effectively worse off than they were, the parties responsible for starting and promoting the war get away without any repercussions, the fall-guy gets locked away in an unmarked cell for the rest of his life (everyone is made to believe he’s dead), the Princess Lemrina is presumably dead (that’s left very unclear), etc.
Then there’s the character I refer to as “Sir Ass-Pull”. At the very end of the series, some character I never remembered seeing before abruptly shows up to save and eventually marry the princess. It wasn’t until I was checking out the English dub to see how it compared that I saw that Klancain actually did a brief, meaningless appearance at the beginning of the show. He had been SOforgettable that I literally did forget about him. So no development of him, no hints to his reappearance, no reason he should suddenly show up, no effort to make us care one bit about the character. Especially considering they had been building up another character (Count Mazuurek) who could have more logically filled the role of Sir Ass-Pull.
Sure, I’ve thought of how I could fix a lot of the stupid plot-chasms in a fan-fic, but then again it shouldn’t be necessary to go to that effort.
Now there IS one thing I would give Aldnoah.Zero credit for, though. Watching it’s “alternate history” which split off from a change in the conclusion of the Apollo program, it made me dust off a story of my own that I had abandoned quite some years earlier (it also involves a change in how the Apollo program ended, or rather didn’t end). Of course, that’s about the extent of the connection between the two.