Nice start to your sketchbook! Rendering seems to be your strong point I think someone else said something similar up the page - but I'd recommend doing quick sketches to study anatomy to really nail that (although it looks like you're on your way already!). Keep it up!
"[...]as we gain facility of hand and travel further afield, we discover that we have a key to unlock the wonders of art and nature, a method of conjuring up forms at will: a sensitive language capable of recording and revealing impressions and beauties of form and structure hidden from the careless eye[...]"
-Walter Crane, 'Line & Form'
The Star Fox stuff is old, but I'm curious, what were you reffing? The N64 poly models, or the original old-school physical puppets they made for the SNES Star Fox manual and Nintendo Power? I LOVED those things. I friggin' want one. I wonder what they did with them. Ah, I miss Star Fox. Fucking Nintendo doing jack shit with the franchise. :/
Anyway. You're on the right track, and clearly improving fast. No advice to offer. Keep at it, Sarge.