The map is a shape you cut out of the dark

Alderen's automap used to be a panel. You pressed M, a grey rectangle appeared, walls were painted on it in a slightly different grey, and every floor in the game looked like the same rectangle with different marks in it. It told you where you were. It told you nothing about where you were.

So we stopped drawing the map and started drawing the hole.

Now the map draws only the floor you have actually walked, plus the stairs down once you've found them. Everything else is left undrawn — the live corridor shows straight through it. The explored mass gets a chalk edge and a dark keyline, and that boundary between drawn and not-drawn is the wall information. Nothing paints a wall any more. The absence does it.

Early build

The effect is the part we were after. A cramped mine floor and a sprawling cavern floor no longer look like the same rectangle; they look like two different silhouettes, because that's exactly what they are. Ten minutes into a descent you can tell where you are from the shape alone, the way you'd recognise a coastline.

It also does something quietly useful for the horror of the thing. The unexplored parts of an Alderen floor are not greyed out. They are not there. You are holding a picture of the small amount of this place you have survived so far, and the dark around it is the same dark you're standing in.