I admire it, but even I struggled with it at times. I think it has fairly fundamental problems. Either you'll get impatient with the light, fluffy first half (as I did), or you'll have problems with the more serious, dramatic second half. Almost everyone's a doll, the premise is weird and counter-intuitive and we still have no idea who this mysterious "father" is. Oh, and the finale does a bunch of things that finales don't normally, although I personally quite like that in this trippy, childlike, brutal anime.
The main problem, as far as I'm concerned, is that the first half's trying to return to empty-headed comedy even though we know how dark Rozen Maiden really is. This is a show where:
(a) a family of seven doll sisters are emotionally dependent on the father they barely even remember, even though he's ordered them to fight each other to the death. They call this the Alice Game. Admittedly death isn't quite as irreversible for a doll as it is for a living creature, but then on the other hand he's also programmed them with self-hating body fascism that destroys their sense of self-worth if they become in any way imperfect.
(b) the last survivor of this deathmatch will win the right to be called "Alice" and to meet Father. They all believe this with religious fervour, even though Father must surely be long dead. He made the dolls decades ago. Shinku and Suigintou were already fighting each other during World War Two.
(c) the dolls (called Rozen Maidens) tend to find emotionally damaged humans for the sake of parasitic energy-draining bonds, as if they were vampires. (It's almost unnerving how easily you could rewrite this into a vampire series.) We've seen in both seasons so far that these energy drains can be life-threatening.
Yeah, cheerful. Nonetheless, this season's first half is mostly about showing us that the dolls are goofs, idiots and infants. My attention drifted. It's meant to be funny. Sometimes it is. The dolls are practically toddlers, both physically (they're small) and in some cases mentally. We meet a new doll called Kanaria, who thinks she's the most intelligent doll and would struggle to be the most intelligent inanimate thing in the garden. In fairness, she made me laugh in ep.3. Her never-ending confidence can be amusing, especially after an unbroken sequence of hundreds of failures so complete that her enemies haven't even noticed her presence. "You're about to experience true terror!"
There can be deceptive depth. Ep.4, for instance, has a theme of dishonesty and denial (both with oneself and others) as it examines Suiseiseki's inability to accept a human. This ends in a scene that's wedding-like, but only until we're reminded once again that Suiseiseki's a small child. "Grandad always used to read to me before I went to bed." There's also cruelty in the puppet show, although not as yet any sense of danger. However ep.5 is then another comedy episode about Hina trying to go outside and send a letter to Jun. (The bathroom door slapstick was funny.)
A further problem is that Season 1's damaged humans have got better. Their relationships with the Rozen Maidens healed them. Jun is no longer a hikikomori and he's got over his near-phobias. He's not yet back at school, but he is at least studying for the exam to catch up on his missed studies. Meanwhile Souseiseki's old age pensioners are no longer being eaten up by their own grief. (Tomoe had never really been broken, though.)
This is nice for the people involved. Good for them. However it's a problem for the series. If the humans have been healed, then there's no thematic balance for the dolls' ghastly, crippling drive to collective suicide. Jun's no longer Shinku's other half. He's just an ordinary-ish schoolboy whose friends are dolls. Meanwhile his sister Nori's almost vanished from the show and Tomoe is only an occasional semi-regular, although she adds something important when she does appear. (Her relationship with the innocent Hina Ichigo is capable of being either sweet or desperately sad.)
After ep.5, I was struggling to see a point in most of the episodes so far. However ep.6 gave us the first of the new generation of damaged humans... and wow. Megu Kakizaki is an upbeat, friendly girl in a hospital bed who refuses to eat, repeatedly begs her Rozen Maiden to drain all her energy and is determined to die. Her Rozen Maiden is her thematic twin, in a way that's both beautiful and devastating. Mitsu "Micchan" Kusabue on the other hand is a happy, successful adult with a job, but she's also the show's most childish human by a long way. She's a doll otaku. She's infantile and she probably needs help.
That's without even mentioning the villains. Barasuishou's an anime-only character, by the way, since by now the anime had been forced to leave behind the manga.
I quite like the characters. Some of the dolls are very silly and/or squeaky-voiced, to the point where I could easily imagine someone finding one or more of them annoying. I really like Shinku, though, and her determination to resist her emotional programming. She's genuinely angry when her sisters start killing each other and the body count is rising. This creates an unusual and rather satisfying inversion for the finale (I think), in that it's not losing a fight that makes you a loser, but instead the fact that you were trying to win at all.
There's also an anthropomorphic white rabbit, continuing the Alice motif, but more sinister than Lewis Carroll's. Personally I find the serious characters more satisfying than the silly ones, but that's until we start seeing the latter caught up in the carnage.
They must have had a bit of a budget crunch in ep.9, incidentally. I'm mildly surprised they didn't fix the relevant scenes for the DVD release.
I like the second half a lot. I think it's manages to go even darker than Season 1 without in any way retreading or undoing what went before, which is pretty impressive. That's what this subject matter needs. I like the ending. I like the way it doesn't cheat and turn into romantic harem nonsense or something, instead playing its doll conceit completely straight. Unfortunately the season's first half feels a bit trivial. I wasn't gripped. After that, though, it recovers strongly.
"Take me away soon, to the empty darkness."