Welcome to Gaia! ::

After two years of drawing only girls, I have finally begun to draw guys. Spanner here is the second guy that I've fully completed... So his anatomy is a bit off still. His legs are a bit short, and that's what making the rest of his body look so big... yeah. No harsh comments please D:

First off, I really, really love how he looks. So cute =3= . I really like how you did the folds in his clothes and the face. And that hand! It looks good overall, except for some things I'd like to point out without seeming [too] harsh.

As you mentioned before, his legs are a bit too short. The lower body is generally longer a bit longer than the torso. And while his lower body is longer than his upper body, the elongated crotch makes his legs look short (that may be why they're short).
His shoulders are also a bit too narrow. Guys tend to have wider shoulders than girls.
And finally, his arms. Anatomically, I don't see anything wrong, but the posture looks awkward. His right arm (our left) is looks unnatural (I can only imagine someone reaching back to achieve that pose without purposely angling it), and too tense for the overall relaxed demeanor that emanates from him.

Other than that, all looks good! heart
He's so cute~

I dunno what exactly you'd call a "harsh comment"... Overall looks pretty good, but, as you've already noticed, the legs are short.

Just an observation, but his pants have no belt loops.
Having a zipper at his crotch could help make it clear that the pants are baggy and that his crotch isn't stretched..

The pocket on the leg to our right seems to be right on his knee whereas the other pocket is on the side of the pants, not the front... The seam line suggests some issues with the leg to our right.