Graham A. Nelson (born 1968) is a British mathematician, poet, and the creator of the Inform design system for creating interactive fiction (IF) games. He has authored several IF games, including Curses (1993) and Jigsaw (1995).[1] (wikipedia)
Writing a really general parser is a major but different undertaking, by far the hardest points being sensitivity to context and resolution of ambiguity.
This means keeping many trails open at once, inevitably requiring a fairly 'parallel' plot. This plot should be discovered rather than announced, so show, don't tell.
At the end of April I archived 'Curses' and Inform, and announced them on the newsgroups.
I don't really believe in 'directions' in art; the rope twists as you follow it, that's all.
I like to employ a form of repetition, in which the same elements recur but in different and unexpected ways. rather than being discarded as soon as they are understood or passed over.
I try to make puzzles range all the way from easy to hard, and to leave many open at once.
I'm rather pleased with the new manuals. I see Inform now as a gauche young adult, having got past the stage of growing out of his shoes every few months.
If you're setting a game during the Cuban Missile Crisis, look through a library. find out what people were wearing, what other issues were in the news, how houses were furnished, what cars were being driven. Especially include things which now seem foreign.
Players very widely disagree with me about what's hard and what's easy. and in a way, 'I won, but it was a fight' is the best compliment a game can receive.
The 'interactive fiction' format hasn't changed in any fundamental way since the early 1970s, in the same way that the format of the novel hasn't since 1700.