Cursed Elf in a Dungeon of Filth

An elf collapses in the woods, having crawled out of a labyrinth with a curse clinging to her that keeps everyone around her from properly registering that she exists. Broke and unrecognized, she has nowhere left to go but back down, into a dungeon nobody bothers naming properly: the Unclean Labyrinth.

That name is not decorative. The place runs on filth, monster girls, and tentacled things that treat the curse as an invitation rather than a deterrent, and the elf's invisibility to ordinary people does nothing to protect her once she's underground. Transformation looms as much as combat does.

Play is dungeon-crawling RPG structure laid over a sandbox you're meant to poke at rather than rush through, exploring the labyrinth's rooms and creatures while the curse subplot threads through what happens to her along the way. Nothing about the elf's situation improves through diplomacy.