The Gostok (interactive fiction)

This is a text game where most of the words are nonsense, and yet it can be played. (I haven't played it, I just like the concept.)

From Aaron Reed's review:

In traditional parser games, you might need to make a map as you play. In The Gostak, you need to build a dictionary. The game is difficult or impossible to play without copious notes on words and their possible usages, filled with guesses, partial information, and out-of-context phrases[.]

[...]

The game is carefully designed to help you learn how to play it, despite its seemingly obtuse surface. Nearly every verb mentioned in text is implemented so you can try it yourself, something rarely true in typical IF. Each new message is a chance to learn more vocabulary, with failures often more instructive than successes. Muckenhoupt wanted a key mechanic to be “words as treasures … learning a new verb is the reward for solving a puzzle.” You might have previously figured out how to acquire a whomm darf, for instance, with no idea what the adjective whomm means (or the noun darf, but never mind).

According to another review, it's fun if you like puzzle games, not so much if you like stories.

Here's the link to play it online.