I usually break my reviews in points, but I think Code Geass will require something very different.
I wasn't amazed by art or sound. Sound had nothing special IMO, neither opening nor ending marked me, voice acting was good but not stellar and music was generally forgettable. Art looked pretty good but some faults like those really wierd looking triangle eyes really didn't make it all look so good.
Not that it matters much because almost everything about Code Geass is in its story.
And it's good. Really good. Really really good. Then it kinda falls. Then it's good again. Then it falls. Then good, then falls. Then good. Then the end.
Before I explain my exact issues with Code Geass, I need to say that true masterpieces are always head and shoulders above mediocrity. Always. If you take what I consider to be THE masterpieces of this decade and the last decade, namely the One Punch Man manga(forget the anime) and Ghost in the Shell Stand Alone Complex(both seasons), even at their worst, when GitS goes into filler episodes for its underdevelopped side characters or when OPM delves into a little too much side characters' side stories, they are still very much above mediocrity and never brought boredom or disinterest.
Code Geass, by this standard, isn't a masterpiece.
Now it is still an overall very good anime and it's absolutely worth watching. It goes into agressive politics and war policies very well. It starts off great with two "opposite twins" characters, Suzaku and Lelouch, one being the paragon of morality, the other being the paragon of success. And for a long time, you think that Code Geass will be an ideological battle between those two, mixed with intrigue, love and war, mystery, lots of attaching characters, and a ton of evil laughs at all of Lelouch's schemes and surprises.
It is that for a long time, but then things happen that turn it all in a wholly different direction. It's hard for me to keep this review spoiler-free, so from now on I'll mark at every paragraph if it has spoilers.
The first thing is that the opposition between Suzaku and Lelouch eventually fades. Suzaku stops being a moral paragon over time and becomes a hateful killer by the end of the series, thus renouncing his archetype. It's a good thing for his character, it makes him grow from a naive boy into a violent boy, but even then this character isn't so interesting. Suzaku as the naive hero who wants to do good by trying to make peace with the enemy who despises him isn't a lot of fun. I doubt a lot of people like him. And he generally isn't worth writing home about. He's here as an opponent to Lelouch, and without Lelouch, forget him.
But since he stops being the naive boy, he just stops being all that important. He just becomes a plot tool, a dangerous foe Lelouch has to look out for.
As for Lelouch, his growth is far more interesting, and if Suzaku abandons his archetype, Lelouch does so too, but in a very different way. Suzaku goes from naive hero to warring brute. Lelouch however shifts after some events from anti-hero, so a hero with villainous methods, to an outright villain. Now just to be clear, I'm fine with villains. A villain can be tremendously enjoyable to watch and I'm fine with a battle of villains as the main theme. The problem is, it sort of throws away everything we'd been taught with Lelouch. He was half scheming backstabber, half hero, someone hated by all who'd do anything for his goals, but who would also try and reach for something greater and better than his opponents. A conqueror more than a villain. But by the end of the series and the last big twist in season 1, Lelouch is literally nothing more than a villain. Which kind of begs the question, did they really want to build him as an anti-hero? What was the point if he was just going to turn into a villain from actions he isn't responsible for?
With that, I am compelled to point the biggest problem with Code Geass past its fairly shoddy art and sound: the lack of vision.
Code Geass several times shows that it doesn't have the vision, or more precisely the writing, to go the full length of its ideas. At several times, the story goes into the very tragic, into berserk-tier stuff even. If Berserk did one thing beautifully when it comes to its main villain, it's show his true intent with extreme precision. Griffith in Berserk is kind, gentle, intelligent, selfless, beautiful, daring, exciting, charismatic, a master in all things and in every way a Lord and a Hero. But his goal requires extreme, monstrous sacrifices, and he'll go about giving those sacrifices no matter what. Code Geass goes that route at some point as well, except while Berserk clearly put Griffith in villain's seat and made him an unapologetic, hated monster, Code Geass just doesn't have that vision.
The complete spoilers here is the arc of Shirley. When Shirley's father dies at the battle of Narita, Shirley goes under shock and emotional breakdown, goes to Lelouch for emotional comfort, and steals a kiss from him while crying her eyes out. It's a perfect circle: Lelouch as Zero ordered the avalanche on Narita which crushed Shirley's father. The father was also a kind and fair man who always treated his family with love and care and never harmed anyone, he was simply a soldier and was at his post. And Lelouch is the subject of Shirley's affection since a long time and now she needs him.
This perfect circle brings about a ton of subjects at the same time. It makes Lelouch question his actions and brings him in doubt. It makes him feel extremely guilty twofold because Shirley should hate him and because he has feelings for her too(something which is never properly shown in the anime but that we're told about eventually). Shirley starts looking for Zero's real identity to get her revenge, while he has to keep on pressing with the corpse-piling even harder. If he doesn't succeed in his conquest, all the dead will have been for nothing.
And how does that perfect circle end? In the course of only 3 episodes, Shirley finds out who he is, tries to kill him but fails, and he uses the Geass to make her forget everything about him, Zero and her father.
What I had expected to be a long-running set of intrigue is solved in only 3 episodes with Lelouch essentially using a Deus Ex Machina to solve the emotional conundrum. He's literally throwing the ball out of the field and going "meh, can't play, it's out", can't feel guilty or fight Shirley.
This is what I meant earlier when I talked about masterpieces and lack of vision. Code Geass had a perfect circle, the Gentle Dead, the Tragic Vengeful, and the Evil Hero. Then instead of going all the way to the end and putting Lelouch in front of the terrible choice of killing Shirley, dying, or managing to stay hidden forever, we just Deus Ex Machina out of it and we move on.
It's even more disappointing for the last arc, too.
The last arc features something that literally brought this anime from an overall 9 to a 8. Code Geass would've still been great if not for THAT awful part. What happens can only be described as the plot equivalent of someone stumbling into a rock on the mountains SO HARD that the rock starts an avalanche that kills 50000 people. Yes it looks stupid, and yes it took me out of the anime very very badly.
What really happens is that Zero/Lelouch is essentially beaten by Princess Euphemia. He admits defeat and accepts her conditions. Then SUDDENLY the Geass starts going haywire, EXACTLY when they're alone with no witnesses, EXACTLY when they're about to make a semblance of peace and give some independence to the Japanese, EXACTLY when Lelouch says "I could have you kill all Japanese if I wanted to".
I liked Code Geass a lot despite its weaknesses up to now. Several times I felt like it wasn't making that much sense or wasn't that fun, but it always managed to eventually give me a satisfying enough explanation later on, and it always made me want to keep watching.
But that part? That really hurt. It felt like shit scenario if I've ever seen one. I think Code Geass, being an anime-only product, with no manga, or novel of any kind behind it, may have lacked the important point of view of a writer who's only in it for the story and dialogue. That kind of focus often helps to build much more sensible and deep stories, and I'm not saying that Code Geass isn't deep, but it sometimes lacks sense or believability, and that part around the end really got to me in the worst way. I was disappointed, annoyed almost, and felt like it came out of nowhere. Never before was the Geass mentioned as "faulty".
It's also bad for reasons beyond plot: this is the second time where the responsability wasn't on Lelouch. With Shirley's arc they essentially threw the ball out of the park. The question to "what do you do in that situation" was never answered. Just Deus Ex'd out. With the ending arc however, the question was never even asked. Lelouch didn't do anything, the Geass did it himself. Where are my deep questions about power, responsability, and the great choices of meagre peace or great war? What of the huge symbolism of killing the people who are essentially the good and gentle ones? What is the meaning of Lelouch's actions when he was essentially put before the fact and didn't really choose anything?
In ideology-driven stories, the most fascinating is observing the distance between dream and reality, between the promise and the realisation. What Lelouch becomes, how he fails his original idea, is a slow growth for the most part, but the key, defining element that changes him entirely doesn't happen because he chose it, nor because of his ideology. It just happens because the scenario demanded it.
And that was a huge letdown.
It's still a very good anime, with deep intrigue and lots of flaws that are brushed over by the main themes and ideas thrown in there. It's enjoyable both at the beginning by appreciating the two main guys' points of view and thinking them over, and by the end for all the fighting between very opposite friends. It has a surprising, enjoyable and well-thought twist at almost every episode. Its characters are relatable and admirable in lots of ways, and almost everyone including the side folk pitch in with their own flavor of relatable, admirable or hateable personalities.
But it's not great. It Deus Ex Machinas out of bad situations, it disappoints, it sometimes just isn't that interesting with all the unwarranted school stuff and teenager crap inbetween a generally very serious and thought-out political intrigue story.
Absolutely worth watching. Definitely not worth worshipping.