One thing I noticed is that the color count is pretty high: it goes up to 144 colors. And though I don't think the piece involves any methods like blurring or gradients, I do believe it's possible for it to minimize its color count, which I believe might help unify the piece at least a little bit. For example, there are certain colors that can be merged together.
Hi Pixetrichor, thanks for your C&C
Yes I know the color number is pretty high. I drawn this piece so long ago, since I'm pretty new to pixel and the cilent didn't require color limit.
Once again, really appriciate!