What makes Colossal Cave Adventure interesting to this day is its own limitations. It's a rickety little game, accepting few inputs as valid. It's often frustrating to convince the game to do what you want it to do. And in being a game entirely in text, the labyrinthine geometry of the caves can be incredibly difficult to envision.

But it is because of these limitations, not in spite of them, that the game is able to capture your imagination. The arcane black box of its outputs makes you constantly wonder just what is possible in the world of this game. The ever-perplexing caves seem fantastical and sometimes impossible, wandering blindly through a maze that seems to elude your understanding. The things that produce these feelings are limitations, and by modern standards would be considered failures. And I can't say I had a lot of fun playing Colossal Cave Adventure. But these feelings are palpable and memorable, and represent a potency in text adventures that makes me want to keep exploring.

Colossal Cave Adventure's own limitations create a vast negative space in which players can fill with imagination and mystery. That's a kind of magic that we should harness more in games.