You added shoulder straps but I feel like the arms are so far back they don't look like they are attached to the body. Also  shoulder straps viewed from the side (flat against the body) aren't likely to be 50% of the arm's width, and currently your arms are 2 pixels wide while the strap is 1 pixel. They do look good though and the pixel limitations don't give you many alternatives.

The shoulders and arms should be closer to the middle of the head, but have a go at physically trying to get your own shoulders that far back and you will appreciate what I mean, I think the shoulders also look a pixel too low but I think it's because your character has no neck. It's reasonable to assume that the hoody has a high collar, but if that is the case I'd still suggest emphasizing that he has a neck. One possible solution is to just remove the front pixel of the collar line. It might make it look like the head is too far forward but if that is the case you can move it back one pixel and the jaw will still stick forward.

Now to the hood. I need to look at some references for this really (it's my first day checking out threads) but having the ponytail cutting into the hood seems a bit odd to me, like it's created a v-shaped hood if you were looking down from above. My suggestion for this part would be to angle it down the curve of the rucksack as that is what it would be resting on anyway, rather than it sticking out horizontally. I'd advise doing the shoulders first though because the rucksack is going to need some work to refit it.

All these suggestions are open to critique too of course, I'm always a student.