The ending to the original Madoka series, as well as the first two in this film trilogy was incredible. It was fantastic and moving and impossibly grand in scale. It ended an amazing show in the most amazing way possible.
It really didn't need a continuation.
This film didn't need to happen.
It's a great attempt, and is probably the best you can possibly do if you absolutely had to follow up the great ending that the original Madoka had, but that doesn't mean it was for the best. It shifts the tone of the entire series and pushes everything further into the weird...
While I can't say I'm disappointed this film happened, I just really don't think it needed to.
That said, I have to complain about the sound design...while that was hardly ever a strong point of the series, the extended actions sequences in this film really bring to the fore how mediocre it really is. It seems like they put in sound effects as an afterthought. Considering the robustness of the art design and visuals overall, listening to the same sample be used for every gunshot was jarring.
Oh well.
For me the true ending will be that of the original series and of the second film. This third film, while good, just will never live up to what the original ending accomplished.