This piece has a Warhol look and feel to it, therefore like the style used and the minimal colors work well. My only crit is the quality of the outlines (nose is the worst). It could use improvements in several places without resorting to selout which I don't believe suits this style.
It has a lot of character, and a nice cartoony sense to it, however you should really try to engross yourself in as many pixel techniques and conventions if you aim to improve. : )
Could use some AAing, especially in the hair. The skin tone is a bit too pink, even for a cartoon style. The 3rd face is pretty cool, looks a bit like Blanka. Nice work so far.
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