The Hitch-Hiker's Guide to the Galaxy

Defined by

(no specification or reference implementation on file)

Text Adventure, Z-Machine

Commentary

I was stuck on this one for a long time, because I couldn't seem to remove common sense from my brain. Whether I had gotten the game stuck in an unsolvable state, or I just didn't notice that it worked, I don't know. When I picked it up again years later, I finished it, but I did get a fair number of hints from other people who had played it, in between.