Just got back from watching this, so let's go, this should be spoiler free (posting from my tablet so please excuse any autocorrect misspellings I miss).
There's an underlying theme to Shinkai's films that I kind of dislike, and it's how he portrays his romance. I find them at best to be clichéd and silly, and at worst to be downright mean spirited. It's like he doesn't understand the joy in love, he doesn't know how fun a romance can be. This film is sadly no different.
It's obvious right from the start what this film will end up being, the OP (I find it weird that a film has a full anime OP anyway) kind of makes it clear from the outset that we should be expecting these two to be together, anything that deviates from that would be a surprise. We don't get that surprise, we get the story of how they came to be together.
Through body swapping apparently. Now don't get me wrong, these parts are fun, genuinely fun, even if some of the comedy (I have BOOBS) didn't land with me, though I found myself far more interested in the microculture of Mitsuha's town than I did the ongoing shenanigans, I feel that a more accomplished director may have gave us a bit of time to soak that in, but we don't really get that, which in the end is understandable because there's a lot to get through in the film, and spending 5 minutes on watching Mitsuha and her grandmother weave ceremonial braided chord would take away from other parts of the film.
The end climax did have me invested, I cared about what happened to the characters and Shinkai had the opportunity to send the film into a direction I would have utterly despised, but this time he resisted temptation and gave me an end to that climax that I liked.
I think my main problem is the shift in focus from Mitsuha at the beginning, to Taki through most of the film. I didn't find him particularly interesting, and he ends up mainly being a vessel for the plot without me ever being invested in who he is or what he cares about. It seems through the film that he's a pretty talented architect, but we're never really shown it in any detail, and we never see if it's something he cares about, so why should we? It also makes the romance vapid, because it's hard to see why anyone would be interested in him, we're told he's a nice guy, we never see it really, he just does what most people might do in such odd circumstances.
The sound design was excellent I must say, not so much the music itself which felt a bit twee and overblown, but the sound effects in just the everyday situations was noticeably very good, it's a weird thing to point out, but throughout the whole film I kept picking up on it.
My main gripe though is the art style, these overly simplified characters just don't gel well with these hyper realistic backgrounds. Yeah they're amazingly well drawn, but when the character on screen doesn't match that level of detail, it just contrasts in a really jarring way. Also, everything looks too clean, they could do with losing some of the detail and making some of the places just look a bit old and tired, Tokyo is a giant city, I can't be expected to believe it looks like it's been hosed down with a giant pressure washer every 5 minutes,and that shrine is supposedly thousands of years old, why does it look brand new? The animation itself is pretty great though (aside from some questionable rotoscoping near the end), even if it does look like I'm watching the film through instagram filters for most the time.
I don't regret spending hard earned to see the film, it's a good-if-flawed experience, and it feels like it's more than the sum of its clichéd parts. It's worth a 3.5/5 anyway.