Definitely a cool start Zaz. A few notes from my perspective are:
Resize the Apple menu logo so it doesnt touch the top or bottom it looks uncomfortable.

I wouldn't use any topbottom lines on the menu item selections, in some instances they are a different vertical height which results in an inconsistent variance.

I think you could probably choose a better color for the gradients which better suggests "industrial".

But these are just my personal impressions, youve obviously got a direction you want to go with so take my opinions with a grain of salt and see what ya get.
Just please, complete this one , its going to fill a void in OSX theme options.