Niiiiice! Looking fantastic so far, Uncle0wnage! Bravo!
Let's do a status report...
Arms: FANTASTIC. They look just about ready to go. I especially love the work on the fingers!
Torso: Almost there. With the upper half of the torso, would it be possible to make the bottom, curvy part of it flat? More like carved wood, know what I mean? Also, perhaps consider making it a *tad* larger. Other than that, well done.
Legs: He still needs those knees to be able to bend them. Also, his legs to be longer in general.
Shoes: So far so good, but see if you can flatten out the sides of the "cuffs", like in the artwork.
Head: Pretty convincing so far! The eyes look great, but see if you can indent them *slightly* inside his head, as if they were carved there before being painted. The lines under his eyes look like they should be parallel to each other, rather than running toward his neck. The nose looks just about right, but I have to ask - is it a separate piece from his face? Because it looks like it was molded out at the moment (though that may easily just be me). Also, maybe round his ears out (they seem a little bit pointy). Finally, his mouth - again, parallel lines are the way to go.
Hat: Looking good so far - I like the attention to detail with the top, as his hat does turn into a sort of bun after the top of his head. His hat is sort of like a beanie or a skullcap that way.
Here; I made a quick mock-up height comparisons for Geno's in-game sprites.
As you can see, he is actually taller than Mario. His chin is above his, as is the top of his head (not even counting the "bun" of his hat). It seems as if he is actually as tall as Peach (without her crown).
In addition to that, I also gave you some extra reference shots, such as what Geno's hat looks like from the side, and the way his guns look when he uses them.
... Again, I don't want to make you feel like I'm breathing down your neck with all of these pointers. I realize this kind of work can't be a simple task, so allow me to say again how FANTASTIC it already looks. I'm simply a hardcore SMRPG fan, so I can understand how I could come off as demanding right now.