Alright! Thats looking
much better!

But once again, we're running into that light source problem, it's not defined that well and it still needs a bit more contrast, I'm also seeing a useless color or two in there:

Man I looooove editing these, so fun they are! Okay, like I said before, you should use a top-down light-source, this piece shows that, now unless your game is gonna be christmas oriented, I think you should change the green to purple or orange, I made it a purple-ish pink in the edit. I took off the side things because then it's easier to give it that 3D effect, especially from, you know, a top down view/light-source, if you'd like you could curve the lines to make those look 3D along with it, though it is tricky. I'll probably edit my edit later, due to it having an odd shade here and there.... for the most part I think it gets my point across.
Remember: It's metal, making it shiny is the key!
Uhh let's see what else? Oh yeah, to make it easier on yourself for enemy variations, doing recolors is pretty useful, though don't over do it.