First of all, the main Menu (Accordion ) and Background (img) look really nice.
The UI looks great but the problem I have is that the elements “category” and “selectable item” are just not distinguishable in a slick way. The bottom margin separation is not enough!
Once you click on something the list loads immediately and your “mouse moving flow” lacks a few milliseconds behind since all buttons look the same.
I get it that you want to keep the number of button-styles to a minimum so that the whole menu is consistent without too much noise colorwise. But maybe you can make adjustments so that it’s faster to grasp for the player.
Rememeber, we are players that want to flick through the menu in the shortest period of time 
What do you think?
PS: This is not a big deal or something. Just something that would make the navigation more enjoyable.