the blade could use more shine. It looks a bit flat.

 Thanks! I'l post the improved pic tomorrow, hopefully it'l be better ;)

All about banding (and about everything else in pixel-art too ;)

Not a bad start. You'll need to give this piece a light source (what little hints there are of one are inconsistent), and also try to build a better palette. Colors at this point don't seem to have been thought of as in relation to each others.
More about this here.
Also as you know, more contrast!

I think you should simplify the shape of this thing, in order to have a good mental image of its volume and imagine how light would act on it and how colors could work to convey this.

 Man, I'm really just getting started, I have absolutely no idea what banding is. I'm redoing it now and I google it but i can't really understand. Could you please explain if it isn't too much?

You've got far too much banding for this to be accepted IMO. Redo it with no/much much less banding, increase your contrast and lower the color count. You've got a few colors that don't read and serve no purpose really but to add banding.