Looks like i'm one of the first reviews here, I'll go in the history books, lol! Well, let me start by saying Tenki no Ko is a great continuation of the form that Shinkai's been in for the past decade starting with Garden of Words. The character designs, story, pacing, art, animation and sound are all top notch as to be expected.
I, however do encourage you to lower your expectations. Not that the film isn't good, it is. Great even and really enjoyable for me. It's just not Kimi No Na Wa 2, which I feel many people will be expecting going in and be disappointed. This is a different type of story and film that in my opinion feels closer to 5CM per second and Garden of Words than to Kimi No Na Wa. Keep that in mind going in. That doesn't spoil anything, the endings are different, before anyone(mod) complains. I'm just referring to the storytelling method and type of story being told. It's much more grounded and is its own unique thing involving a much more realistic narrative and a fresh MC backstory/internal struggle.
What do I mean by that? I don't think I'm spoiling anything here by saying that the plot while being fantastical, is very grounded in nature. A huge part of Kimi No Na Wa was the magical aspect, here you've got that, but the story is much more rooted in the characters, their interactions and relationships. The whole "weathering with you" is more secondary to the actual inner struggle that the MC is going through and the hardships he's been through which will resonate with many.
Art was top notch as I said before, usual Shinkai style with amazing detailed environments and amazingly detailed character designs. Sound was also really good, soundtrack was great and definitely set the tone for several scenes during the climax. Can't wait for it to be released. Additionally the sound design with rain, weather and other day to day things sounded extremely lifelike and added to the immersion of several scenes. Animation was mainly stellar, but there were a few choppy scenes that I noticed when the characters were running or moving rapidly and I found it a bit jarring, not the biggest deal, but it was there. Mainly, the way the characters' necks and legs moved.
Pacing was good in my opinion, I didn't ever feel overwhelmed by the story, confused or lost. I felt that the script took me from A to Z properly and characters were given their time to shine. Main story and subplots progress smoothly.
Now for the negatives. The CGI was, in my opinion, kinda iffy at times and was a bit subpar in general. I personally think that if I can tell there's CGI being used, it's bad. That could just be me, but there's several scenes where the CGI is really noticeable and so I have to dock points for that. That's my personal definition. I also saw very little actual growth out of the MC from start to end. I know it's a film and not a series, but I wish I would have seen more of his development. I like to see Protags grow and evolve over the course of a film and learn new things. I did not get that in this film.
Additionally, By the end of the film, there are still some unresolved questions and plot threads that I really wish would have been answered during the film, but I do have the Light Novel and am hoping that we will get more answers in that. I also found the ending to be really abrupt and not well led into. Again, think 5CM per Second and Garden of Words type endings. I reiterate, that's not spoiling anything, I'm just comparing it to comparable works and types of stories. The ending is its own thing and completely unrelated. I just dislike how it was abrupt and left more to be desired. I like to see endings eased into. Hopefully the LN will tie up what the film couldn't.
Overall, I really enjoyed it and while it won't break records like Kimi No Na Wa did due to its more grounded nature, it is a really solid film with a unique story, beautiful character designs, great soundtrack and amazing art that I definitely recommend checking out if you can. I imagine there won't be many people reviewing it on here for a year or so, so if you have any questions regarding the film or Light Novel, feel free to hit me up/add me.