Art: Interesting, but lacked motion.
While Gundam 00 had interesting locales and mech design, it employed too much static animation for a show ostensibly about giant fighting robots and dynamic, expressive characters. As a result, the fights feel unsatisfying and short, and the characters lack depth of emotion.
Exia, for example, is a mech with multiple swords built for intense close range fighting. However, it spends more time in combat relatively motionless or even off-screen while a minor character explains something, which is another annoyance: Fights are constantly intercut with scenes containing less animation, ala Dragonball Z. Two seconds of expensive fighting to ten seconds of minor character snapshots.
Likewise the characters suffer from this as well. When people express an intense emotion, they often cannot stop themselves from moving. An angry man trembles in rage, or paces, or gestures frantically. A sad person tears up or covers their face. Gundam characters, even in the privacy of their own rooms, Gundams, or hallucinations, will stay completely still until their mood changes. These statues with moving mouths will attempt the deepest wails of sadness without the tiniest shift in their diaphragm. They'll slam their fists against a console and then stay there, perfectly tensed, for an entire monologue. In other words, they attempt dynamic, intense emotions with simple, static body positions, and the show suffers for it.
It's a shame, since the animation was quite enjoyable in the few minutes that they went all-out.
Sound: Mostly well done, with good music and satisfying sound effects.
Exactly what it says on the tin. Explosions felt big, lasers sounded lasery and the music was set to the emotion of the scene. Good job, but nothing moving enough to leave an impression.
Story: Oh God.
Indeed. A mysterious organization known only as "Celestial Being" wages war against war with the use of Gundam Meisters, special individuals that pilot powerful mechs known as Gundams. Thematically, the show attempts to communicate the pointlessness of war and a deep political conflict in addition to varied and interesting battles (in space and on land); it's an incredibly ambitious undertaking.
So did Gundam 00 deliver fast-paced action, deep and engaging drama, and convince me of the pointless loss that is war's only end? In a word, no.
I've touched on this in the animation section, but Gundam fails where it's most important for an action drama to succeed, namely the action and the drama. We're here about the story, though, so let's look at the drama.
Rather, let's look at the melodrama. :LIGHT CHARACTER SPOILERS HERE:
Gundam 00's vision of drama plays out like this: introduce a main character with a super mech, have them collapse into a sobbing heap at the first minor setback (I.E. pulling out a trump card too early, but still accomplishing the mission), then tell us about their tragic backstory to explain why they acted the way they did. Introduce a supposed master tactician, have them make a single mistake and softly sob in the emptiness of their cabin, and then have some characters talk about why said tactician's tragic backstory justified that action. Long story short, if there's something in the character's past that explains their actions and lets me sympathize with their plight, show me that first! Explanations after the fact don't feel satisfying, they feel tacked on and cheesy.
:LIGHT CHARACTER SPOILERS OVER:
Another storytelling sin besides telling instead of showing is that we are constantly given stories of characters that are completely pointless to the plot. This is a bad thing and I'll show you why.
The Gundam's blade sang a deadly duet with the enemy's sword, creating a harmony as fragile as a life. A feint, a thrust, a parry, a riposte, as the strikes cut closer and closer to the hearts of the pilots. With a final slash, Exia sliced a fatal opening in the defenses of his rival as Saji finished the last of his homework.
"Man, what a day", he thought. "First my girlfriend wanted a watch, then I had to finish my class assignment and even stay up late. Ah, well. I wonder how my roommate is doing? He doesn't seem to be around often."
"I AM GUNDAM!", cries the pilot of Exia as he stabs through the enemy mech. Mission accomplished.
Having minor characters sit around and talk without even slightly influencing the main story is like showing a random person going to the bathroom in the middle of an intense battle: when the scene doesn't add to the story, it detracts and distracts from it.
Character: A diverse, well designed, overacting core cast weighed down by a diverse, well designed, useless mob of side characters.
Two sections here, because the characters were well designed and drawn, even if they were cruelly mistreated by the story and script.
Design: Astounding. The show deals in global conflict, and it feels like a lot of care was taken to make each character look like where they came from, from the anatomical form of the characters to the way they dress. the Gundam Meisters have uniforms that color coordinate with their Gundams, the royal palace feels royal, each country has a different look and culture, etc. Really well done.
Development: Poor. About one fifth of each episode is dedicated to minor characters parroting plot developments the main characters already covered without adding anything. There is an entire side story that barely connects to the plot and also doesn't influence the plot. Even the main characters tend to repeat things about their own or others' backstories even when things are apparently resolved, halting the flow of events for another retread of stagnant details.
Value: Negligible.
Gundam 00 is worth watching once just to see what not to do in a mech drama; it's a classroom lesson and not much else. People looking for an engaging story will leave frustrated, and those looking for tight action and combat will wonder why so much time is spent with people standing around and talking. The threat of watching Gundam 00 can motivate an indecisive group to commit to an anime, however.
Enjoyment: A waste of time, but watchable.
Even subpar anime often contains moments of greatness or enjoyable portions. Gundam 00 did have some memorable moments, but they were unfortunately overshadowed by the boredom of multiple plot recaps and needles exposition. After weighing the time spent watching this anime against the enjoyment and stimulation it afforded, I came out negative.
Note: My first review. I welcome feedback on quality; however, don't trash my work simply because of differences of opinion. If I could have handled a section better, please let me know. Just don't your explanation be "It's bad because Gundam is awesome, k?"