I do not agree with everything Cyangmou said. I think it is the gray background and the purple outline that create the 'blurry' effect and not your anti-aliasing. I put it on a white background and it looks fine. The shading is very clean and authentic. Well done!

Also, I encourage you to explore your own style of pixel portraits, by using GBA FE as a starting point.

From what I can tell, you nailed your recreation. I think it looks great!

I didn't draw the references. They're the only available images I could find of this character's prototype portrait, and I basically tried to recreate the actual portrait from those poor-quality photos. That being the case, most of the chunky/poor shading isn't something I would've stylistically chosen to do if I were merely doing my own take on it.

The drawing is ok, but I guess the main thing which bothers me is that it looks really blurry.

You applied the AA not to smoothen things out, but rather as second outline which gets brighter, but you don't break it up - and that causes a "blurring" effect.

On a nitpicking note: the eyeline and the earline doesn't seem to match up properly as you drew it. More importantly, you won't even see the rear ear out of this perspective.