Thank you very much for the great feedback, as for the hair i based it on a sprite (normal size vegeta) a friend did and gave me to turn it into NGPC, i know there is alot of DBZ characters in this styles thats why i decided to draw it by myself instead of basing it of other existent sprites in NGPC style.
Thank you once again, and i'll try to keep your recommendations in mynd. :)
It's fairly hard to justify giving these criticism as they're really just NGP based stuff. I'm assuming you used a lot of bases, the hair for example looks like a slightly more detailed version of the GBC's Legendary Super Warriors Vegeta.
With that out of the way, I'll move on to actual criticisms. The contrast between shades blends too smoothly, giving off a gradient/pillow shading effect. As well, some of the outlines seem a bit rough, for example, where the hair meets the forehead. I'm assuming you kept the outlines because it looked good on the NGP counterparts, and granted that's true, it also only worked because of the low resolution. When you're dealing with sprites of this res, the outlines just come off as thick and unneeded.
For now, that's all I really have. I'd just suggest working on the actual shading style first, and fix the outlines later on after you get some more practice there.
Good use of diagonal pixel perfect lines! Also I like his hair :) (unlike in most DBZ drawings)