Here's something I whipped up to test a new method of shading. The linework is not so hot (look at the way the belt-area, groin and upper leg leg are angled, notably. The hand is a tad too big, too, but I guess it's better than a too-small hand. I have no excuses for the poorly angled feet-blobs.), but at least it looks more "3D" than my other stuff.
I played all four of those GBA games. They were amazing.
Perhaps more foundational figure drawing would be beneficial. You seem to be lacking in the fact that you don't really know what a person
looks like, let alone how the body
works.
Best advice I can give to practice on proportion and figures is to grab a pencil, go to a museum and sketch statues, or sketch the people looking at the statues until the security guards have to force you out.
Note also how this character seems to be standing on an incline, how his feet are dramatically bigger than his pelvis and thighs, how his head is bigger than his pelvis, how his hands are wider than his waist, how his back is inhumanly straight, how his lower arm is not only larger than his shoulder and his upper arm combined but larger even than his face, and how his lower legs are larger than his entire torso.
His face, though less of a concern in comparison to the bizarre features of his body, consists of anime-eyes (which, for now, you should avoid), a little black triangle for a nose and a horizontal blip to symbolise the face.
That is not what a face looks like. You need to get past simply drawing symbols instead of faces. They're
recogniseable, sure, but only barely - and with them, you'll languish forever in the city of Not Artists, straddling the Valley of Suck.