Story: Generally, the main story arc is great and interesting to watch, with only a few glitches around the middle episodes where the creators seemingly pull these gigantic city destroying flying fish things out of their asses - but after this the story is explained wonderfully. However, the few filler episode which they stuck in were really unnecessary - they did nothing to develop the plot and gave only minor insights into some of the characters. These episodes really should have been put to better use through expanding on the backstories of some of the characters that were only looked into during the last few episodes - or just expanding the last few episodes in general, as they were quite rushed. Namely, Dominic and Anemone (although her story had to be told quite late into the show to keep the tension), but there were some characters that were there just to hold places; like Woz and Jobs, that deserved more.
Animation: Throughout the 50 episodes, Eureka Seven has excellent animation for the mundane, but ramps it up to another level as soon as the action starts taking place - seeing the LFO's battle it out with the trapar waves flying out behind them is amazing, and the panoramic landscapes which are shown are breathtakingly detailed in their depiction of an Earth torn apart by war. Unfortunately, character design isn't so great - the main crew of the Gekko are all good; in fact most of the characters in the show are great - if a bit generic, but then we see characters like Dr. Bear who are ridiculously out of place with everything around them; and having the main monsters of the show be giant colourful plankton was just a bizarre choice on the creator's part - they really could have been done better. There are also occasional moments where glaring CGI pops up out of nowhere in the form of a Nirvash that sticks out like a sore thumb.
Sound: Incredibly well done throughout! The background music is placed perfectly in every episode, no matter how much a single particular joke tune grates on my nerves. The EDs and OPs are great, complimenting the show's progression at whatever point they are used.
Voice acting, too, is amazing. Not a single voice is out of place, being exactly how you would expect the characters to sound and expressing the emotions of their characters fluidly and without fail.
Characters: One thing that's amazing to look back on once you've finished the series is how the characters developed through their ordeals, growing constantly, if erratically, throughout. It had some amazing individuals to work with (Like Anemone, and Dewey) and for the most part, pulls the viewer into their plights with great ease. Unfortunately, the development of each character is completely and utterly erratic, eventually leaving only the main characters of the story and a few of Gekkostate's members with a comprehensible back story. Too many episodes were wasted on the slow paced depiction of life on the Gekko, leaving very little time for some of the more interesting characters to be explored in the last few episodes.
Overall: An excellent series; and one which I'd love to watch again, but key flaws prevent it from being as good as it should have been, so the very most I can give it is: