Hello Durrahan!
First let me tell you, your pixelart is really good.
You've chosen great colors and your AA is great, i usually don't like AA and seldom use it but I'll probably try using your style in the future.
You hue shifted colors and that mouth you drew is great, do you have any online place where I can find more of your art?
Now for the things I think you could work on:
Most problems i found were due to lack of symmetry and some anatomy mistakes, they are more slip ups than mistakes.
Try to imagine your forms like a 3D figure to measure the height of the facial features.
You also had a pretty strong tangent in the chin(it was connecting the chin to your hairline) this kind of thing makes you lose a lt of depth.
Here are my notes on your original:

And here's how i would change it:

Hope this helps you a bit.