I honestly hated this movie.
I'm not trying to anger people, but I cannot see what everyone likes so much about this movie. I found it slow, annoying, and found a lot of problems with the whole plot. Just to name a few problems with the plot:
1. Chiaki came back to see the painting, but had to leave before he could.
Makoto knew where the *beep* painting was and could have taken him to it, time was frozen.
2. Why couldn't Chiaki buy another time device to come back and see her?
3. When he was used his last time jump and was stuck in time, he could've pulled a "Back to the Future III" and had a letter sent to his family in the future to come get him.
4. Some disaster supposedly destroys mankind in the future, and instead of doing something about that, Chiaki comes back to see a painting... which he fails to do.
I highly disliked this film, but stuck through to the end because I was expecting more. Perhaps someone can explain the appeal to me.