Fantastic edit! Thank you so much for taking the time to critique. I am definitely inspired to improve this piece! I think I'll work on it more tonight. 

its a start... so id suggest u shouldnt start with fancy stuff like aa right away. it rly doesnt work here, for example aa is seldom used on 45° or straight lines....it just makes them look blurred... also it should be kept for the final refining.. u should make sure ur pixel clusters work as good as possible even without aa....

about the flatness... define ur lightsource well, now it looks like there are bout 4-5 different lights, also try to imagine the volumes of the stuff ur drawing, the roundness, curves, try to literaly feel them and paint light and shadows around them.... its also helpful to use a lot of contrast for the first shading layout, so u get a good impression wether it works or not, ur contrast is very low, and the color ramp rather boring, try hue shifting aswell. with gold it works always very good to add red/ violett to the shadows... 

heres an edit