Awesome suit design!
I think you could define the edges more by adding highlights. On top of that, you could try adding textures such as scratches and dirt.
One thing I like to do is find a random metal texture on google and put it in overlay and set it's opacity lower. You can always mess with the layer blend modes! See which one gives you a better look.
I'm sorry if the advice and feedback is what you're looking for since I am relatively bad at giving feedbacks
I realized that I was going way ahead of myself on this concept design or character design thing by tackling themes that are I guess a bit advanced for me. I forgot the fundamental of going small first, baby steps if you will. That said, I made this "Garebear" through Zbrush and Photoshop, and I am really happy with it cause for the first time, it feels like I didn't try hard, and it looks and feels finished to me. I know I got a long way to go, so practice, practice, practice. I hope you guys like it, and feedback is always appreciated!
Cheers!