
I only edited the right side of the image for lack of time.
You're suffering from banding (or was it called breaking? Pep! Help!) where you layer lines of AA over themselves. This creates an unpleasant 'banding' effect like a gradient that breaks at the same points, hugging a contour. This isn't good in my opinion.
Furthermore, your dithering needs to be cleaner, more controlled, and shaped better, I feel.
Your colors were good for this, but some near identical shades were to be separated, as well as the far darkest shades brought closer to visibility.
You're progressing a lot in a short time. Catch your breath and ponder.