The Hoover Dam has beautiful Native American art symbols through out it on the floors and Art Deco bronze architecture on the Visitor center gates.
It has marble tiled tunnels and very steep stair cases. The stair cases are soo steep they have gates about every 15 feet so that if you were to slip. You would not continue to tumble to the bottom. There are hidden passageways blocked by mysterious doors with dark corridors lit by orange and blue safety lights.
The texture of the concrete inside the dam corridors is actually a wood relief from the planks used to mold the concrete to the wall.
I understand it is a game and in order to put that amount of detail into it would have probably run down the system even more. And for security measures the game company was probably told they could not create an accurate model of the Dam. But I gotta say they did pretty well with what they could use to create the environment and portray the overall feel of the dam.