You don't get to watch sci-fi movies like this very often and believe me, its a work of art which is criminally underrated in my opinion.
A pure love story put into motion in a futuristic world between two people who you won't imagine would make a perfect couple. The power of perseverance and selflessness driving their love/relationship ,which i think can be explained with a quote from the movie,
"I want to see her smile again, even if it's not reality, even if it doesn't belong to me"
-Katagaki Naomi
(Spoiler Warning)
This is to clear a misconception about why the movie is animated in a clingy 3D manner or why is it in 3D and that is what sets this movie apart and is a piece of artwork which isn't praised enough. So to put it into perspective, the whole movie was in 3D because it was all the recorded past or the world within ALLTALE.
Only the last scene, where Naomi wakes up from his coma, is the only scene in the whole movie in 2D or the orthodox animation we love, is the REAL WORLD.
I think, now upon re-watching or knowing abt it, it will change your perspective.
HOPE THIS REVIEW/INFORMATION HELPS.THANK YOU