I don't like the mixing of pixel scales between the font and the rest of the art.

The stains on the paper look blocky because they're build up of largely rectangular clusters. I think some refinement there would be nice. I'm also not sure they need to be quite so blurry/smooth, stains in books are often fairly sharp (but faint).

The characters are a bit hard to read against the background because their values are so similar. Maybe make the colours on their clothing lighter, so that they stand out against the dark background.