It's all good, man! I know exactly how you feel. Sometimes you take a chance and sometimes it works out, sometimes you pay the price.
The same thing happened to me with the recent contest. I didn't realize until it was too late that I had been pixeling on a light background. It wasn't until I saw it in my gallery (I have a darker background) that I realized that my anti aliasing wasn't working anymore.
If it's any consolation, I can tell the skill and effort you put into this even on a darker background. And the animation doesn't take any hits by the style of background that it's against.
The cast shadow looks worse than I thought it would on a dark background, but I am not going to change it because making this gif took so long.
Well pixeled but a bit hard to read. Even at 2x the hair in front of her face reads as a tongue, and while what we can see of her face is well done, it's not quite enough to give us proper context imo. Combine that with the general limblessness made me unable to tell what I was looking at for a bit.