The more you show us, the more I like it.
I like it with legs, but making it multi-part will let people use it as a floating ball if they wish so.
I too like the texture. Looks like something that would happen to orc equipment: getting so dirty that moss and stuff starts to grow on it.
I'm looking forward to seeing this finished, and alternatives. Perhaps not just different faces, but also a completely clean and untextured robot.