Also having finished PMMM....it's....meh honestly....It starts off fine and cute, but the dark turn ust seems like it came out of nowhere, and exteme punishment of characters who did not deserve what happened to them (Most specificly Sayaka and Mami.) Seriously Sayaka does not get to come back? She only had to be killed because she was turned into a witch because she was griefing??!?!? So what, a Magical Girl has to ALWAYS BE HAPPY?!?!?! THAT IS STUPID! What did she do to deserve getting axed off for....no real reason...I liked the character, but the circumstances behind most deaths.....are complete BULLSH*T! Also, Madoka is supposed to be a strait up goddess at the end and she can not create a new universe where her best friend is still alive? Wow some friend Madoka is!
The animation is stunning and the characters are great, but it takes itself WAAAAAAAAYYYYY to seriously, and feels like it is being dark and gritty just for the sake of being dark and gritty.
Personally, I believe that the creators were trying to go for something more gritty and darker. They wanted to experiment with the magical girl genre to show that, usually, it's not all fluffiness and cuteness. A lot a believe commented saying that since it was darker, it was more complex and deeper.
But that's just my opinion.