The article links to a previous article discussing methodology for this. The prompting is pretty extensive.

It is difficult here to separate out how much of this could be fixed or improved by better prompting. A better baseline might be to just give the LLM direct access to the text adventure, so that everything the LLM replies is given to the game directly. I suspect that the LLMs would do poorly on this task, but would undoubtedly improve over time and generations.

EDIT: Just started playing 9:05 with GPT-4 with no prompting and it did quite poorly; kept trying to explain to me what was going on with the ever more complex errors it would get. Put in a one line "You are playing a text adventure game" and off it went -- it took a shower and got dressed and drove to work.