To me it just looks like you made a normal pixel image, and then doubled the height.
That squished one doesn't look bad. As a general rule of thumb, the distance between the eyes is usually the width of the eye, it might look a bit better if you did that.
Yeah, it's mirrored all but a pixel in the eye, I think. It looks a bit stubby with normal pixels, but I suppose that works too. Looks a little monkey-like... Maybe that says something about me. :p
http://i39.tinypic.com/15pml2g.gif (height halved / squished)
It's nice, and good job, but I have to agree with surt. Maybe you could add a few horizontal pixels?
And I may be wrong, and if so I'm sorry, but am I seeing a mirror image? It looks like you might've just copied and pasted the right/left side after doing the other...
Quite good, but really doesn't look like it was meant for tall pixels. Looks much more natural to me with square pixels.
As mentioned, this could have been done much better with regular sized pixels.
Very nice job as is, though.