Dark Castle (Mac OS Classic, 1986)
This game has a prerelease article
Prince Duncan sets out to topple the Black Knight's throne... literally.
The published version contains a single gameplay demo, stored in the Castle Preferences file as "Default", which depicts a Beginner playthrough of Trouble. There is no known way to access the recording functionality seen in the above dialog; deleting the DEMO resource merely results in no demo playing, while deleting the entire prefs file keeps the game from launching at all.
A similar inaccessible dialog exists in the 1988 sequel. User-recordable demos were finally enabled in 2008's Return to Dark Castle.
If launched on a 128K system, the game crashes with a flickering system error dialog before it can even manage to bring up this explanation.
The Dark Castle series
|Mac OS Classic||Dark Castle (1986) • Beyond Dark Castle • Dark Castle (1994)|