This thread caused so many thoughts, I didn't know where to begin.
I'll try not to go too crazy...
I think people want to play a game that is "good" - whatever that is, and it varies depending on the person. Some people like hard puzzles where you probably end up having to look at hints; other people don't like puzzles at all, or don't mind straightforward ones. I've read quite a bit on the intfiction forum, and the answer is... it depends. You'll never please everyone.
So I'd say: write the game that you'd want to play or for an audience you'd like to target (for example, for me, it's my non-IF-playing family), and then be sure to give it to people to test, as we're all too biased to judge our own games objectively (either good *or* bad. I'm often harder on my stuff than others are).
As for my preferences: I'm not a big puzzle person. I'm not good at writing them, and I don't particularly care to work them out, especially if it involves some sort of "guess the verb", "guess the noun" or "try to divine the bizarre thing the author intended." More specifically, I like a game with some sort of hook. In particular, I like games where you can do things and go places (which is why CYOA is so hard for me to get into), but more than that, I like a game that makes me feel something, preferably not frustration. But it doesn't have to have those as long as it has *something*, where that something could be anything, which I'd know when I saw it but I can't say definitively. Not helpful perhaps; mostly I'm trying to say there are no hard and fast rules. Just make it good.
I must confess that I haven't played much IF, at least not pure text adventures. I have dabbled a bit, but I'm not extremely well versed. Hopefully, that will change over time. I have played some, and I have played some graphical adventures, and I have played RPGs. (I've also played lots of other kinds of games I don't need to get into.) The games I have enjoyed the most (non-IF) have been games like Zelda and Myst Uru Online. They both have "places to go and things to do". The latter in particular has inspired me, as the game definitely has puzzles, but it's all driven by mouse clicks. The puzzles revolve more around what you do with the world, not in how you instruct the game. There is no typing, and yet I never missed it, as things just did what I expected or at least did something when I didn't know what would happen. I'd love to be able to do that with IF, where I can have puzzles and other challenges in my games that are more about what to do in the world as opposed to figuring out how to input it. (I've never been a fan of "parser as puzzle", where you as the player know what to do but part of what you have to work out - by deliberate design - is the magic words to type.)
I'm looking forward to seeing what you put together (perfect or not)!