I think that when doing a large character like this its important to use perspective to give it the presence it should have.
in relation to the pipe flooring that you included, the character should probably be in a slightly top down perspective.
correcting the perspective also lends itself to correcting the anatomical issues, since you can better describe the torso with value as it would fall on a character at that angle
here's a crude edit of how the character would look if you applied some of these changes
take note that in the original the character is facing us, the viewer
if you want the illusion of it existing within your game to be stronger you should try to make it look as though it's facing forward relative to its game world
in relation to the pipe flooring that you included, the character should probably be in a slightly top down perspective.
correcting the perspective also lends itself to correcting the anatomical issues, since you can better describe the torso with value as it would fall on a character at that angle
here's a crude edit of how the character would look if you applied some of these changes
take note that in the original the character is facing us, the viewer
if you want the illusion of it existing within your game to be stronger you should try to make it look as though it's facing forward relative to its game world