So, what is IF? You have probably heard of Choose Your Own Adventure stories, where you are able to make choices at various points in a story and it branches depending on what you decide. They are often called "text adventures".
IF lets you type in what you want to do and the program updates your situation. Most use pure text; some use pictures and text; some use animated images. (I always wanted to write stories that play out interactively inside virtual worlds -- I call it VRFiction. There have been some brilliant such works, such as "The Last of Us" and "The Last of Us Part 2"). But in spite of all the potential for graphics, plain old text IF is still often the most complex.
Galatea has around 30 verbs, but more than 150 nouns. You can type in "help" (without the quote marks) to get hints, such as some words the program will respond to.
Most IF has some kind of quest, or story, or puzzle that you are supposed to solve, but Galatea is unusual in that it is a character study which can go hundreds of different ways, depending on what you do or say.
Expect to be frustrated at first, but it can become quite addictive to play over and over again, making different choices and getting different outcomes.
You can download Galatea as a file to be run on your computer, or you can play it online:
http://pr-if.org/play/galatea/
If you want the downloadable file so you can play it offline, you can get it at:
http://ifwiki.org/index.php/Galatea
or
https://www.ifarchive.org/indexes/if-archive/art/if-artshow/year2000/
You will need a reader program. I recommend Gargoyle, which can read many Interactive Fiction formats. (Crossposted from https://miriam-e.dreamwidth.org/335198.html at my Dreamwidth account. Number of comments there so far: