This movie wasn't as good as I thought it would be, but it was definitely unique. I think what annoyed me the most was the voice of Arceus. In the trailers it sounded cool because Arceus was mad, but outside of Arceus being angry the voice sounded like that of an old woman and didn't fit.
Otherwise, I thought that the Egyptian-sounding music was pretty good and that the "legend" of what happened in the past was really interesting. I was really taken away by the battle between Dialga and Palkia in the 10th movie, but in this movie I don't think the battle scenes were great. It was unfair, even though it was three against one.
The visuals when traveling through time were amazing, as well as those of the dimension of Arceus. The 10th movie actually drove me to tears, but this one didn't, though. I think this movie was only a bit better than the 11th one. The identity of the person behind the real betrayal was a shock, I will admit, because everywhere I looked before the movie said it was someone else.