Yeah, there definitely should be more landmarks and generally different architecture across the level to distinguish areas. The simple truth is that I ran out of time to add in more detail and assymetry so it has ended up quite boxy and samey. I'm intrigued by your depth perception comment though, especially as you mention the fog which is intended to help with that. Do you think it's just more detailed architecture that's missing for you or maybe textures would help?
Imma be real, I wrote that review right before going to bed and was really tired and not thinking the clearest, thinking back more clearly I don't think the fog really contributed to the depth perception issue at all. I mentioned it because I was mostly trying to think in terms of the background being a very flat gray a lot of the time, but most of my issues with depth perception happened at more close to mid range where the fog wasn't really in effect.
actually going back into the game for a sec I think a big missing thing that would've helped way more with the depth issues is object shadows. A lot of my issues were more with telling where objects were laterally in a room, so I'd regularly undershoot bombs or have a hard time judging where exactly to place my antigrav beams.