I remember Nibble published a text adventure game, but to preserve the mystery for the reader who typed it in all the text messages were encrypted with some sor

I remember Nibble published a text adventure game, but to preserve the mystery for the reader who typed it in all the text messages were encrypted with some sort of trivial cipher. It was absolute hell to type all that stuff in ("ZPV BSF JM B....") and KeyPerfect was no help.