@faassen @futurebird
Went there and followed a link to this gem:
"The basic maze generating routine had been partially written by a stoner who had left. I contacted him to try and understand what the maze generating algorithm did. He told me it came upon him when he was drunk and whacked out of his brain, he coded it up in assembly overnight before he passed out, but now could not for the life of him remember how the algorithm worked."
https://www.techspot.com/news/85622-nobody-sure-what-makes-atari-2600-game-entombed.html