Lots of texture is good, but theres almost no shading on the golem itself.
What I do is texture and then apply a shaded gradient over it.

Looks good otherwise.

Can you show me an example or explain how you do that? Sounds a lot easier than shading textures...

I think it looks fantastic but i might be biased =P

Sorry, I forgot about the forums considering they have been new-ified.

I am not the best explainer, but basically, I Do the shading first (Usually a simple gradient with rounded shading on shapes.) Take account in the direction of the light.

On top of that I would add a texture, which i get away with doing by adding Darker/Lighter versions of colors, as well as secondary colors.
You already do this.

I'm not too much of a fan of black outlines these days, but thats just my opinion.

If you want a tutorial, check out "So you wanna be a pixel artist" It's probably the best one out there on spriting.
http://www.petesqbsite.com/sections/tutorials/tuts/tsugumo/chapter3.htm

my opinion:
good, i was more imagining something with a neck.. but its good, just needs a little work with shading and such as them guys said