To me, it comes down to how much the experience will be different on a replay.
- A one-move game is generally built around the conceit that you’ll play it several times, trying different single moves to see what happens.
- In The Wand, half the experience is playing it a second time with knowledge you couldn’t have had at the beginning of your first run.
- Counterfeit Monkey is full of alternate solutions to puzzles, and has a “hard mode” that disables the most obvious solution for each one: if you replay in hard mode, you’ll need to go further off the beaten path. (I tried to imitate this in Scroll Thief, which also has a hard mode disabling the most obvious solutions.)
- The conceit of Night Road, like many Choicescript games, is that you build a character and then see how that character would approach the story; a different character might go through it entirely differently.
- The goal of “tactical” games like All Things Devours is to optimize your approach until you have a winning run planned out. (Suspended, Lock and Key, and Varicella are also in this category.) You’ll often need to restart instead of just restoring a save if your approach wasn’t correct.
All of these make the experience very different if you play it a second time. Something like Zork, on the other hand, will be basically the same every time you play it. Once you’ve solved all the puzzles once, there’s not much left to experience. And most IF ends up falling into this category: replayability just isn’t a design goal for most works.