As Kir had come to spend subjective weeks down here, the dungeon had started to make a weird sort of sense to him. For one thing, even if the features of the dungeon weren't consistent, there were tendencies. Like the tendency of the portals between floors to become either larger or more numerous the "higher" up they went.
Some doors led to dead-end floors; places with no discoverable way in or out. It was exploring and backtracking out of these floors that had taken most of their time, so even though they'd been through more than a dozen floors, largely by air, there was no way to tell how far they were from the exit.
The only way Kir could guess they were advancing toward the surface was that the floors were steadily growing more and more alive.