Spoilers: Read at your own risk.
The movie I was expecting to see was something that combined the best parts of "The Girl Who Leapt Through Time" with the best parts of "Wolf Children", two of my favorite films from Mamoru Hosoda. I wanted to see a heartwarming journey of recognizing the importance of family through time travel shenanigans. I was a little disappointed when this was only partially realized.
Story: 6
The story had a lot of promise for an extremely heartwarming story of young Kun coming to appreciate his younger sister, Mirai, and his family, even though he initially hates Mirai for taking his family's attention from him. I fully expected the story to be focused on Kun being thrusted into a fantastical world with the future version of Mirai. I imagined that through this journey of trying to get back to his family, Kun would gain more understanding and sympathy for his younger sister.
Instead of doing that, the movie repeated a certain pattern: Kun throws a temper tantrum (which makes sense since he's just a kid), have him be thrusted into the past alone to meet one of his relatives, and quickly come back to the present after he's learned something from them. I found this formula to be actually quite interesting since it went against what I had initially believed the movie to be, but I quickly realized that the movie gave up on having deep emotional connections with any of the relatives since each relative took up each other's screen time, forbidding any real development with any of them.
If there is one good nugget of the story I can appreciate is that Kun does show change as he goes through these time traveling vignettes with his relatives, and the at the end when he has a moment with baby Mirai, it almost felt like the ride paid off. Almost.
Overall, I appreciated the story for its back and forth time traveling, but I strongly believe that the film would have immensely benefited from more focus on Kun and Mirai. Mirai shows up about three times in the entire film, which is more than any of the other relatives, and I still couldn't feel a strong bond between the two, even at the very end. The story was decent, but it just lacked oomph to really pull off a satisfying ride.
Art: 9
The art, of course, was great. There were so many sequences that were beautifully animated and really brought fantastical worlds to life. They even had sections where they animated characters in CGI (very much like they did Houseki no Kuni) for some scenes. I saw some great scenes that reminded me of the time jumping sequences in "The Girl Who Leapt Through Time" and fun familial scenes from "Wolf Children". The art, in essence, was what I wanted the story to be.
Sound: 8
Voice acting for both dub and sub were both pretty spot on. I was particularly surprised by how good the dub sounded, though some scenes in the dub I found somewhat uncomfortable because of the way the lines were delivered (I won't get into these scenes, but I was extremely uncomfortable). If I were to recommend sub/dub, I would recommend the sub - I found it to be far more impactful.
The soundtrack was full of heart and I often found myself immersed into the scene purely because the of the songs.
Character: 5
Kun was the only one who had any character development, with nearly everyone else in the main cast being static and unchanging. I actually liked this, since I loved the initial team dynamic of Kun, future Mirai, and their dog Yukko at the start of the movie, and I looked forward to seeing them be forced through different time travel adventures and hardships together. But this team almost immediately dissolves and Kun simply faces his adventures alone in quick and unsatisfying time hopping bursts. I soon became somewhat unimpressed with Kun's development, even when he did show incremental changes in his character. In short, I really wanted to care, but it was just extremely hard to.
On the other hand, the supporting characters, such as the mother and father, had their own developments that I saw through very subtle scenes. I found these legitimately fantastic and heartwarming. I would even daresay that their struggles were more interesting than any of the main characters' struggles. If anything, the supporting casts' struggles and development were in danger of overshadowing most of the main characters' struggles in terms of catching my interest and emotional investment.
Enjoyment: 6.5
Despite my comments above, I did appreciate the movie. I can't deny there were moments that the culmination of the music, art, and some emotional moments got to me. I blinked away a few tears. But I think this movie could've had me bawling. I wish it did.