These maps are used to indicate relative positions of hostiles, weaponry, power-ups and hazards and to help convey the atmosphere of a location in conjunction with the adventure text.
They should not be considered as a usual 1 square=5' style dungeon map. They are slightly more abstracted than that and do not adhere to a particular scale - though the rooms in The Flayed Domain can be assumed to be much larger than your average "dungeon room" in an old school RPG, since they will be host to fights involving guns!
The Flayed Domain takes the form of a pointcrawl adventure, with a diagram showing connections between areas or 'points' . Six of the points in the adventure are further elaborated using these pixel art maps.