I thought I'd ask about a particular feature, in case anyone has done it already: a menu that pops up when a link is clicked, itself listing one or more links. For example, if I click on a link "door" in the middle of a passage, several options pop up: "examine", "open", "kick down", etc., instead of displaying these in the normal way as "Examine the door", "Open the door", etc.
I'm also interested in real-time game-ey mechanics. Has anyone, for example, implemented features of MUDs with Twine? I mean something like a real-time text adventure, with NPCs acting over time, or random events happening once in a while.