I think this is an interestingly designed OC. I like the really simple but effective color scheme of red and white. It uses one of the more emotionally powerful colors but I find the white to really cushion the harshness that the red color can be sometimes. I find the OC's design to be pretty fun too. You basically split up her costume into two halves, but switched the coloring in the eyes. The only thing that's probably worth picking at is probably the the fact that your OC has two different eye colors. It just feels a bit awkward looking at somebody's eyes when one eye is grabbing more attention than the other. Reds grabs a ton of attention compared to neutral colors like white.

I can't really make sense of this person's anatomy though. I see two exposed pieces of skin on the body but I have no idea what that is. They're shaded like they're two separate pieces.

What I really dislike is something that probably isn't your fault. There are little bubbly shapes all over the place, suggesting that you've been reading really bad tutorials. I see unnecessary checkerboards all over the place. The outlines aren't smooth and look like shifted pixel rows.

They say the most common purpose of dithering, at least among actual professionals who know their craft, is to blur the boundaries between two colors. Dithering does not need to be for faking new colors as you can easily just add a new color to your work. There is very little use for dithering among professionals except maybe making something look purposefully dirty.

We can also pay more attention to your lines by counting line segments. For example, starting from the white pigtail, look at at the outline defining the top of the head. Here, I can describe that line as a diagonal line 6 pixels long, then two horizonal line segments both 2 pixels long. Then, there's another diagonal 4 pixels long. Then, we have lines 6, 9, then 12 pixels long. It's not a smooth line because the rate which the lines are changing lengths doesn't appear consistent.

[link]

^Here, I made a little change to see what a line looks like if we change the lengths to be diagonal-6, diagonal-3, then horizontal 2, 3, 4, 15, then curving back down with 6, 4, 2 and so on. If you count your lines in this fashion, you will have much more control over the quality of your work.

Then there's the little thing about outlines being shifted pixel rows. Don't feel like explaining what I mean, but there's a little something written by a very experienced pixel artist who has written something about it:

[link]

Then, there's another tutorial that might be worth checking out: [link]

Pixel art is one of the weirder mediums as the general pixel art community have come up with guidelines on how to best arrange your pixels to draw what you want, and the guide above outlines pretty much at least lightly covers almost everything.

If you would like to find a community that can help you with pixel art, I would recommend a place like this: [link]

I don't participate in that community myself, but rather I lurk there. You can pick up a bit of knowledge if you go around reading a few critique threads there. dA is very nice, but a little too nice sometimes as people usually don't bother helping others out. Communities like Pixellation will do their best to give their best critiques, that is if you're up to it (though, personally, I'm not up to it myself, haha)

Overall, a piece that had a great start with a great subject, but unfortunately we had swallowed a bit of bad advice as we didn't know any better.