What's with the laying-down dude's near lower pant leg? In the back, it looks like a skirt or something.
His head looks kinda flat.
It looks like his right pec (our left) is coming too far left.
I'm having a hard time imagining what he could be laying on and where the viewer is in comparison.
It looks like his shoulder is too bulbous in comparison to the rest of his arm...like samus' shoulder. *
In the smaller one, it looks like that grey you used on the shins and chest are a bit too neutral when set among the surrounding hues of flesh. There's no kind of buffer, and it looks very out of place. Also, in such a small piece where every pixel counts, the grey makes the character look quite cluttered unless zoomed in to, like, 3x, and even then it's somewhat confusing. I like the low contrast on the large piece, but not so much on the smaller one.
*Yeah, you know way more about anatomy than me, so I may be quite wrong.