It’s looking pretty good so far!
One thing I have been playing around with is another version of the raycasting extension that lets you add a floor and ceiling to the tilemap. It’s great for making enclosed spaces and buildings. Some variety in width of the passageways and possibly some rooms might be nice too. (but idk if that would detract from the appearance and horror aspect of it)
Here is the link to the updated tilemap extension: 3d Rendering with floor and ceiling! - #8 by neintoes
Here’s an example of a game that I made a year ago that was kinda like yours but with the floor and ceiling raycasting extension: https://arcade.makecode.com/S71331-42439-19644-88443