I agree that for it's size it should have more details. It just seems a bit unfinished. Although with a bit more detail it could be very cool.

Antibon - lots of pieces actually do use that method eg. http://pixeljoint.com/pixelart/14250.htm For determining what is and isn't pixel art (note there is no 'true' definition ) the focus ought to be on the aesthetic. It'd be good if the definition of pixel art specified a level of detail, antialiasing, neatness that is appropriate for pixel art. As it stands, this piece is neater than http://www.pixeljoint.com/pixelart/39717.htm . However, I personally would prefer if it looked more like http://www.pixeljoint.com/pixelart/6028.htm and shrinking it a bit could help re-pixelling and achieving that aesthetic. Very good for 13!

Amazing for a 13 yr old. I can't crit this as usual, because by checking yer gallery I see you better understand the concept of pixel art now, so what's the point?

(stray white pixels between fingers of right hand)

I agree with TINC, this piece could be made in a paper then scanned, reduced to black and white and finally colored. That's not truely pixel art.

Yes, but that piece has plenty of detail and would lose a lot of its quality and detail if it were smaller, this piece could easily be smaller and still convey the same level of detail.

Also, I'd prefer a transparent background since the white isn't really doing anything for the piece and just seems unnecessary.
Also also, if you didn't pixel "NinSpriterx" by hand, then it needs to be removed.

Its not too big if that was the case then
this http://www.pixeljoint.com/pixelart/4328.htm would be too big.

I think is too big.