[Level Design] Technical LD - Unreal Metro City Project

Here is my level design document for a game project based on a metro city on Unreal Engine.
I was inpired a lot by Metro games, it's a adventure type of game where you evolved on a underground areas.
The civilisation lives in poor condition and some city has got better chance in this universe where high class people defend it by putting military checkpoint in the tunnel.
For the moment I just make some research and level design prototype on paper and Unreal. I have made document for starting area in the tunnel, some passages and one poor city / ghetto and one high city protect by checkpoint