By the way, I should point out that there is some ambiguity in my definition. I've separated Myst from adventures because I've basically said it's not interactive enough to qualify. I can certainly see someone saying it is, and I hope he will because I'm eager to talk about the puzzles.
On the other hand, I'm saying that Photopia
is interactive enough to qualify, because although the player has no control over pacing and direction his actions are crucial to the story. This is a subjective call.
Edit: Ah, I hadn't seen Kurufinwe's response yet.