Some Custom Sprites

[Mega_Virus]

If thats your edit from his original I'm sorry to say his original looks better, his looks more metalic than this one.

And adding numerous shades of colors makes it more readable if the pixels are located in the right area's, besides making digitized sprites detailed comes to blurring a tad of area's cause there small to the eye, for example looking at something tiny in reality you see it blurred out cause our eye cannot see it well same goes for sprites/art when attempting to make the sprite/art tiny and graphical.

This is what he needs to work on:

Here if you look it shows the correct shading pattern that you kind of lacked I know because I worked on your sprite.
It also shows that when adding more shades of colors it makes it more graphical, I happen to ruin the original size but you can see already see which one looks better unfortunately you have to work with less colours so the right one would be your best bet for your digitized sprite.
deciding on your base color to shade doesn't really matter that much what matters is you do the correct shading pattern towards the shape you want to present for us.
So a square would have a square shading pattern and a circle would have a round shading pattern, I'm almost certian you know this but some people get confused when working with an unperferct shape.