The impression I get from TFA is that this is about "unfinished/unreleased" games more than "lost" games. A "lost" game, film, or work of literature would be one that was published or released, only to disappear again from the historical record.

https://en.wikipedia.org/wiki/Lost_literary_work

https://en.wikipedia.org/wiki/Lost_media

Several lost games from the text-adventure world are listed here:

https://www.club.cc.cmu.edu/~ajo/in-search-of-LONG0751/2009-...

https://ascii.textfiles.com/archives/2923 (BlackDragon and Dor Sageth)

https://web.archive.org/web/20140528184628/http://games.wwco... (The PITS)

https://bluerenga.blog/2024/09/02/adventures-1974-1982-lost-...

https://bluerenga.blog/2024/10/27/adventures-1974-1982-lost-...

(To be fair, many of the games listed in the latter two posts seem to be known only via advertisements; it's conceivable that those advertised games might never have existed. But in many cases we know a game existed because we have testimony from people who played it at the time.)