Captain Earth... the somewhat odd title turns out to be a title given to people who fly giant robots to fight ill-explained aliens (well, Captain is, but whatever), spoiling my hopes that this was going to be an awesome Captain Planet spinoff. Who are the ideal candidates to fly humanity's last chance at saving themselves? Hormonal teenagers is the answer, for anybody who hasn't seen an anime before. It has something to do with their "libido" (yes, the actual word they use is "libido"... more on that in a minute).
So, what's good in Captain Earth? Well... umm... the animation is above average. Being a show from Bones, they have plenty of animation talent on hand and the show looks crisp and sharp. The characters and mecha designs range from acceptable (most of the "good guys) to rather outlandish and fan-servicey (any of the villains). The music is also ok, it was made to order for the show, but it's not really particularly memorable. For me, the intro and outro themes aren't the worst things this season, but I'm not really a fan of this type of music so not much comment there. Some of the earlier episodes that don't involve giant robots aren't half bad, but they're quite rare. Expect at least one screening of the same full 2-3 minute transformation sequence just about every episode.
Alas, what is bad in this show? The answer to this is: basically everything else. This show suffers from "Bones Syndrome," which is them fumbling around trying to recreate the success of Eureka Seven. Regardless of whether or not you like E7 (I'm on the fence), since the success of that Bones has made many shows that ape many of its features, typically for the worse. I'll run through an itemized list of these as they apply to Captain Earth to save you time:
Lots of gibberish words. Captain Earth has an especially large number of them and they're just plain stupid. There are whole sentences made almost entirely out of BS made up words and they're rarely (if ever) clearly explained. AND the choice of words are freaking retarded; some choice examples are "Livelaster", the aforementioned "Libido" (some sort of spirit energy that may or may not come out of your genitals) and "neoteny". The last one is actually a word, but its real meaning is only vaguely related.
Plant imagery. Everything, especially stuff related to the character named Hana (Japanese for 'flower' for the zero people who don't know this) is absolutely oozing plant metaphors and symbolism. Creepily these are often rather sexual, focusing on the reproductive facilities of plants, which is doubly creepy in the context of the plot.
Unbearably lame dialogue. OH YEAH WE'RE SAVING THE WORLD WITH FEELS. SCREW YOU EVIL, WE'RE JUST GOING TO LOVE YOU TO DEATH! And so forth. The characters are so goodie-goodie they'd be at home in a Teletubbies episode.
Vague plot. There's like some aliens and stuff and they have to fight. Also there's bad [human] people who inexplicably seem to think that the best way to save the world is to sabotage the people with giant robots at every turn. They make basically no visible progress towards their alternative plan.
Giant robots (duh). To be a proper Bones show, the giant robots have to be powered by whales or some shit like that. Here, they're powered by what seems to be the sexual energy of their young pilots.
Emo. Expect random interludes of angst, minor key soundtrack and darker colors. But don't worry, none of the notable characters actually die despite the show pretending like they will over and over again.
Anyway, this show is dumb. Don't waste your time; even if you adore Eureka Seven, this show is Bones trying to cash in on something you love with a half-assed copy.