You nailed with the art style and color palette. The texture overlay adds a layer of strangeness that transports you to a vintage videogamey space, in a Vermis style, which works perfectly with all the weirdness that populates these tunnels. Also, I think it was a good idea to show the verticality with a side biew, instead of trying to solve everything isometrically. I'm gonna use that approach in the future rather than overcomplicate the main isometric map!
Great work!!