I played the game and liked it more than I thought I would- not that I thought it would be bad, but I thought it would be okay. I originally didn't intend to read the source piece, but I liked the game so much that I ended up reading it anyway. I really like the drawings. I like the look of the paper, and showing them as children added a strong sentiment.
One thing that I noticed was that the movement of the sprites felt extremely jarring.
Because of the music and the art working so well together, and the intro with sound instead of appearance, I was quickly immersed, only to be just as quickly un immersed (?) with the quick movement of the Aunt's sprite. I think that slowing down the entrance would do a lot, especially because then Owen's entrance would look like he was in a hurry at the normal speed.
I think that changing the speed of entrance would also be another way to show the difference between the Aunt's mood and the step mom's mood.
I'm excited to play your other games, and I'm glad I took a look at this one.