There are some cool examples already mentioned and I expect other people can come up with a bunch of examples with really good writing and worlds so I thought I’d mention a little sub-genre of IF which I have a real soft spot for, which are IF games that do interesting things with word play or parser.
So here are a couple off the top of my head:
Ad Verbum by Nick Montfort: it’s basically a little collectathon, but the twist is that it plays lots of fun wordplay games. For example there is this area where there are rooms in the 4 compass directions, and in the North room you can only use words starting with N, and S for the South room, etc, and so you have to figure out appropriate synonyms for both getting the object you need from the room, and then leaving the room. And there are various other little word games it plays in other areas.
Rematch by Andrew Pontius: is a game where there’s an extended parser so you can write quite complex commands, and the idea is that you get just one turn to do something, and after that something terrible happens. So the whole game is about figuring out the one very specific command you have to type in order to to prevent the disaster from occuring. Good fun! Another example of the one-turn-only approach is Aisle by Sam Barlow, but that’s more about going really deep with writing into a single moment, and not about solving a puzzle.
The Gostak by Carl Muckenhoupt is all about figuring out who on earth you are and what you’re actually supposed to be doing because all the important words are presented in this fake gibberish language. Here’s the general idea:
"Finally, here you are. At the delcot of tondam, where doshes deave. But the doshery lutt is crenned with glauds.
Glauds! How rorm it would be to pell back to the bewl and distunk them, distunk the whole delcot, let the drokes uncren them.
But you are the gostak. The gostak distims the doshes. And no glaud will vorl them from you."
Anyone else know some good parsery/wordplay-ish IF examples?