yuiiiiii ^_^ the most cutest/ funnist character ever 
from the great anime k-on!!
had a lot of fun making this, think ill draw more spirtes more often ^^ most challenging part. the guitar 0-0
but had some help from my epiphone les paul standard :D
reference pic >http://imageshack.us/photo/my-images/259/koncompletecustomen1147.jpg/
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The guitar should be simpler to fit the sprite style.
Also the line work (meaning the actual pixel clusters since there's no outlines) need polishing.
Try to make better use of the 'natural' pixel angles so the whole looks more fluid, esp if you're not going to AA.
Nice pose and anatomy =)