I started this anime with high hopes judging by other reviews here and on other sites, ended up needing a mental floss in the end with a good anime.
This will contain spoilers as in my opinion, one can't show the flaws of the series without going into spoiler territory. Contains one spoiler for Madoka also and Yuuki Yuna.
What I liked about the show: The soundtrack by Yuki Kajiura and the voice acting.
What I didn't like about the show: Everything else.
The art is 1990s style, guess it worked in 2004, this can be overlooked today on old shows however.
What I didn't like is the plot and characters. The show starts on a mystery note, then evolves into a comedy with mystery accents, then transforms into something dark involving character death and ends in a comedy like nothing happened while also ridiculing and forgetting the character sacrifices (or craziness) in the end, like nothing happened. Forget the yanderes tried to kill us (will go back to this one), now we're friends again and laughing.
The characters, most of them are walking tropes, yanderes, tsunderes, you name it. Apart from the main character almost nobody acts out of their trope. They kill because their tropes require it.
I am glad to see that today many anime have evolved from this. Characters are much more likable in many series. In this one it's just appalling to see characters acting funny, then being transformed into killer psychos, then returning to their own selves.
As for the plot, you cant ignore everything that happened in the series and reset it. Maybe its that I don't like characters being brought back to life and I enjoy series like Akame ga Kill, Fate, Madoka where the characters stay dead. I still remember that I thought (with fear) Mami would be brought back to life in Madoka, but it never happened.
I think it's a lack of respect to the characters and to the viewer to invert the story via a WTF moment in the last episode. Not that Evangelion did not have a WTF moment in the end, not that Madoka Rebellion did not have one, or even Yuuki Yuna (multiple of them in fact), but dead characters stay dead and are remembered for their sacrifice (Gin Minowa - in Yuuki Yuna).
From comedy to drama and back to comedy wtf (as you won't be laughing like the characters in the end). I recommend to skip this one.