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.

Writing a really general parser is a major but different undertaking, by far the hardest points being sensitivity to context and resolution of ambiguity.

What I would pay much more attention to are the few points where the player can inadvertently make a career decision. Most players end up back-tracking, though some actually enjoy this.

I try to make puzzles range all the way from easy to hard, and to leave many open at once.

For a fortnight nobody at all emailed me, or posted a follow-up. Doesn't anyone care, I thought? It turned out my newsreader was broken, and hadn't posted at all.

I don't really believe in 'directions' in art; the rope twists as you follow it, that's all.

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.