I would not wish to spoil the plot for anyone looking forwards to this, somewhat hyped movie. It is a very, very slow movie. If you are not a fan of 98 percent actionless movies that deal with day by day activities you will not like this. I must stress that that is not why the score is a 5.5, I am a fan of slow anime in many instances.
Where a place promised in our early day loses points can be attributed to many things. First they don't give you a very solid hook, even by standard of slice of life animes, the first portion progresses at a crawl and has an unpropotionally small amount of the development in both plot and characters in the movie, despite the time it takes up. However, the pace and degree of intrigue the story inspires does spike up towards the middle, when the main characters life away from family and friends is fleshed out, and his thoughts on it come to light, though it sort of drifts off at the end into a lackluster ending.
The setting is a good one, and distinct factions are set up, though I use the term distinct loosely as the narration does a poor job of saying who's who. This ties in to the political elements of the story, which feel somewhat tacked on, other than the fact that the war has seperated a character from their family.
The movie tries hard to be profound and scientific, not as forced as a lot of anime, but certainly not as successful as "good" anime. Little is ultimately explained about the "science" of the movie, and you are often left scratching your head at why certain characters are behaving the way they are. The ending is so vague, though it touches on the theme of coping with the loss of loved ones, and dealing with distance. The themes of seperation and reconnection is the main thing the plot had going for it.
I didn't take points off for it, but it's worth it to note there are absolute plot holes/logical inconsistencies as well. For example at one point someone steals something very important from a place that is very heavily gaurded, and their escape simply isn't shown, nor explanation given.
The animation here gets the movie a lot of points. A lot of people probably could not cope with the slow start up the movie offers, without the allure of the animation. Thankfully from the slow to interesting parts the animation remains top knotch, with the exception of the weird plane graphics near the end. If you've seen 5 cm per second your in for more of the same goodness!
The sounds here is good, though aside from some Violin, there's no real soundtrack to write home about. By no means bad or sub par audio in general.
The characters were mostly misses. The points earned here are mainly for the primary character Hiroki, who has some interesting thoughts, and seems to have developed somewhat as the movie progresses. As for the secondary characters they develop minimally. Due to the nature of the story, the female character does not develop at all, and the other male lead certainly grows, but no legitimate development could really be said to have taken place. Most slow paced stories thrive off their characters, but there wasn't much to thrive off of here.
Unfortunately a cool setting, great art, and interesting concepts are mostly squandered in this movie. I wanted to love it, the name itself is awesome, and I had no idea what to expect. But at the end of the day it is a very "meh" slice of life anime, that wanted to be more than it was. My recommendation only goes out to those who REALLY are looking for a relaxed slow pace slice of life anime that delves into dreams and "science" to beautiful animation with a theme of loneliness.