Yeah, I get confused when people try to claim Zelda and Zork are "role-playing games." That just doesn't make sense to me, since they don't have any sort of leveling/experience point type deal.

I agree also that text adventurers are fundamentally different than graphical ones. It's not like you can just map Zork onto an engine like AGI or SCUMM and still have the same game. One important thing you'd miss out on is the all the wordplay.

The biggest problem with text adventures (IMO) is that there are just so many things you can type in, that it's often difficult (if not impossible) to rely on trial and error. The games with the more "limited" interfaces are much easier, since even if you aren't precisely sure what you're doing, you can just keep clicking until something works. It's harder to get yourself totally stumped.

Of course, I think you could argue that text adventures (esp. the successful ones) aren't "natural language" but rather "adventurese," a type of pidgin English developed after playing many of these types of games. For instance, we all know that typing "I" or "inventory" lists all the items the player is carrying. That's not natural language. I never see my wife carrying bags of groceries and say "INVENTORY!" Likewise, I don't tend to describe how to get places by saying "N, S, S, E, S," and so on, and rarely use the word "EXAMINE" unless I'm playing one of these games!