if hes putting them in a game (which im pretty sure he said he is) then he wont need shading. in most games that are platformer horror (castlevania) there isnt any shading from a light source.
That is so not true. They are lit from the top.
And I agree with Feron, there are some pretty random hilights.
Also, the dithering, along with the random hilights, is making everything look very messy.
I like 1, 2, and 4. The rest are kinda meh. 1 and 2 are the only ones with clear lightsources.
The big dude's left (ours) leg looks kinda too twisted, especially with his feet facing virtually opposite directions. I think that leg should be more facing the viewer.
The new one, no offense, is pretty dumb looking. I like the head and the arm, but that thin sticklike torso and those legs are, as chigsam said,

.
I think you really need to simplify these dude. They're just too small to have all the detail you're trying to pack in there be clearly visible. This is especally eviedent in 2's chest, what with the horizontal lines and all.
3 looks ridiculous unbalanced.