needs room for improvement
The problem is there's to many manly features you gave to the character. The most obvious is the face(like the 45* angle you have on the left chin bone and the general composition of the face) but there's a couple others; like how the shoulder line is larger than the waist, size of hands and the overall excessive length of the midsection.
On a side note it's generally confusing when you do work like your piece "caboose"- stuff that's fairly spot on proportionally. I imagine it turned out good because you probably referenced a picture of master chief, so you ought to keep a collection of pics, both real and drawn, of various poses and shapes for things like this.