It was pleasant.
I loved the interaction you have to do, to understand what's going on in the girl's life. How she's somehow in a different universe on Day:2539 and is able to create the a world to her desires. Also, the story was very simple and, it wasn't explained of course, but it was beautiful in my interpretation. Going along with the storyline I think the art style was well suited for the animated music video it is detailed, pretty, scenic, and flat-out I wanna live there type of thing.
I do want to criticize the main characters looks; of course she was in no way ugly I just think that they could've made her more detailed I guess... She didn't match with the scenic backgrounds that she created. However, I have no complaints on the looks of the male figure that I interpret she misses and her younger self.
So in turn with all that I am gonna give it a overall 9, because I'm a sucker for giving out good ratings even if I did give it like three 10's and two 7's for the rating portion.
An I want to make this very clear; if you just want to look at something beautiful that contains pretty okay music, and a short story than I suggest you watch this. Only gonna take 9 mins of your time.