As the author of For A Change, I am astonished that anyone would think it was a good testbed for an LLM text adventure solver. It's fun that they tried, though.
The idea was that it'd be good example of having to navigate somewhat foreign but internally consistent worlds, an essential text adventure skill.
The audience I had in mind when writing it was people who were already quite experienced in playing interactive fiction and could then be challenged in a new way while bringing their old skills to bear. So it's sort of a second-level game in that respect (so is 9:05, in different ways, as someone else mentioned).