A good start!

A thing you should watch out for is the use of too many colours, especially ones that are redundant. In terms of anatomy, his arm is too low, making it look like it comes out of his torso rather than his shoulders. Even at such a small scale, anatomy is still important, at least to get the general shape down.

I'm unfortunately not too good at anatomy, but here's my attempt at fixing some of the issues with your piece without radically altering it:



I've done the following:

Reduced colour count to 8, you had many colours that were so similar they effectively served no purpose but to artificially raise the colour kind. This issue can be solved by creating a palette, even if you do edit it on the go, it'll help make your colour and your colour scheme cohesive.

Changed the position of the arm and legs, in order to be more anatomically correct. Such issues can be really glaring and undermine an otherwise good sprite.

Changed the sword and it's size and reduced eliminated banding, but kept the angle/pose.

Reduced noise/unneeded pixels that added nothing. I think you wanted to portray a sort of texture, but i unfortunately have no experience with that, sorry. :/

Reduced dithering to better convey the size of the character, but still kept it.