This unfortunately is not going to meet PixelJoint's definition of pixel art. It's a bit difficult to define cleanly to an outsider, but as a general rule, any brush that automatically blurs or anti-aliases its edges will not qualify.
For a more rigorous definition, please read section I of cure's pixel art tutorial.
They are cute portraits for sure, but as Pheno said, this isn't a fit for the gallery. If there is sprite art in the game, you're more than free to upload that but this piece doesn't qualify, sadly. ♥