huashas
Some might say this much chessboard dithering is bad, but it's a matter of taste if you ask me. Some feel nostalgic and some think it's mediocore and easy to do. I have been there myself too, so saying anything foolish about it is just making an idiot out of myself. From my experience it's been a fun stage in learning pixel art. After having enough of chessboards, I recommend experimenting with different patterns of dithering and textures.
It seems like you grasp the basics of anti-aliasing, but there are places you have too little AA, some places have too much AA and some AAed spots have banding. Banding means two lines of pixels indentical next to each other. This usually appears in different colours in shading or in a simple shapes surrounded by stable layer of AA pixels. This banding effect appears on the "Belas" eyebrows and succubusse's corners of the mouth. See how soft they look compared to everything else?
8 stars for doing a pixel piece at this size, I believe it took you some time. Anatomy and clothing doesn't reveal much distracting flaws, although I'm not very fond of the animeish faces. Good job overally. Don't stop here, you can get alot better than this.