Immediate feedback:
Navigation in all menus should be possible without removing my hands from the position you've asked me to place them in.
If you tell me that the game is played by pressing Left and Right Ctrl, I should be able to navigate all in-game menus without moving my hands away from those two buttons. At worst I'd say it would be acceptable to force the player to use the arrow keys to navigate, but there's no reason LCtrl, RCtrl, and Spacebar wouldn't be good enough to navigate through a menu.
This may seem minor, but it's an unnecessary point of friction for the player and those are generally best avoided.
Other than that, I love the concept and the theming and I am looking forward to playing more of this in the future.