Okay, so gonna go part by part here...
I am particularly impressed how the movie not only retells the original kanto journey, but also weaves back in a once-long-abandoned plot point with Ho-Oh. While weaving the new hotness with Marshadow in felt a bit forced in some aspects, the story had nice pacing and even had some tension at the climax that ultimately was resolved not with raw strength, but by the bond between Ash and Pikachu overcoming those odds. Overall, all that occurred worked quite well even if some of the older parts were abridged for the sake of moving the story along.
First off, Ash's design seems more in line with his Gen V and Gen VI designs which is a nice change from the excessively cartoonish art style I've seen from his SM exploits. And the character designs of the supporting cast are definitely quite something as well. Secondly, I like how they played around with color and shadows, adding atmosphere and life (or lack thereof) to the film. Not breathtaking or anything, but it worked.
Not much to note here. Not too intrusive nor breathtaking persay, and yet evocative when it needed to be.
Besides Ash and Pikachu's obvious OTP-in-the-making, the other supporting cast actually kept my interest. His traveling companions, both from Sinnoh (Gen IV remake, anyone?), each have their own goals independent from Ash. The female one is determined to show her mother (who I am convinced is Cynthia) that she is worth something, and the male companion is a professor wannabe and seems to be quite knowledgeable in a few things as it is. Then you have the brutish 'rival' character who has Alolan pokemon and the conviction that might makes right in direct opposition to Ash's 'friendship is magic' policy. In any case, I would've loved to see more of these characters and learn their past as well as witness their continued growth in the future. Who knows if that'll happen though.
As for the pokemon, again, Pikachu is the center as a support to Ash. We finally learn why it doesn't like to be in its pokeball (which Ash had carried with him all through the film), and they take things a few steps further than they had ever done in the series with their relationship up to this point. As for the other pokemon, the butterfree plot thread becomes a side-story that kind of resolves itself with less investment than the original, whereas the Charmander sideplot comes full-circle in the best way possible. Then there's Marshadow, which again I feel they did kinda push in for...reasons. Maybe would've been better in its own movie, but I guess they saw an opportunity of sorts.
It was definitely worth watching. Most pokemon films are just a supplement to the anime, but this effort of retelling and revamping made the Kanto region seem a lot more vast and alive than the prior time around. Hopefully should we travel to it in USUM, it will live up to the hype...and the Pokemon Company can follow this up with something just as nice.
Overall, I give this series a 91%.