Simply moving
There has been a few difference games that I've truly enjoyed. First are 4, 5, and 6 Differences by Ivorydrive, because they had animated segments, making it feel alive and adding the challenge. This however, I enjoy because it's very moving thanks to its bittersweet story.
There isn't much I can about difference games, since they are simple enough in terms of making it work. Also hard mode is really, really hard due to needing to see subtle differences (missing shadowing sketch marks?!). The meat here is the story, which I said, is very moving with a very fitting musical score, so props to SoS as well.
There are a couple of complaints,one is directed towards image #8. I didn't really get until I got to the end of the story and looked at it again. It's more of a perspectives issue since the "camera" seems more "grounded", because of how the background looked as opposed to being more or less "bird's eye". After knowing it, it reminds me of the Japanese fairy tale "Tale of the Bamboo Cutter", which is about the Moon Princess Kaguya, after reviewing the images again in the gallery. (like the feathery top of her dress to the swan robe, and some connect rabbits to the story, since I see a rabbit in the moon in the second to last pic, although the gallery version showed the alternate version.)
Another is that since the images are raster instead of pixels, I would use the zoom in feature in Firefox to see all the little details, but at the same time, notice some of the layers are a bit off, and can give away the differences (depending on difficulty).
Excellent moving story, minor flaws in the visual aspects. Princess Kaguya is one of my favorite fairy tales/folklore, and it felt like a retelling of sorts. Here's a 10/10.