This is beautiful, but it would be so much better if you toned down some of those very sharp lines, IMO. It's a stylistic choice though.
This is really fun! Great colours and shading. Imposing and comical all in one.
Very cool design. I like the color combinations of blue and gold against the darks. The shape of the legs is especially good because even though it's mechanical you avoided making it look rigid.
The actual palette control can use a lot of cleaning up though. There's 204 colors here and included within are partially transparent pixels (which this site normally doesn't seem to allow from what I've seen) and colors that are only 1 or 2 points of difference. I reindexed this in photoshop with only 100 colors and it looked nearly identical, so there's a lot of wasted colors in the palette.
It looks very organic to me, in a good way, almost like it was grown. I know the brown and gold are supposed to be metal but it almost looks wooden. The dark brown area in the middle looks like wooden planks and the legs are like vines. Again, I don't think it's a bad thing; I think it would be interesting for it to be almost plant-like. The whole thing looks very supple.
I do agree with tanuki and CELS. And when your color count is that inflated there is no reason not to have better anti-aliasing. Areas in particular that I see are the radiating rings in the blue area and the darker lines in the middle of the large band of gold.