The adventure game "Day of the Tentacle" had the previous version of "Maniac Mansion" included. According to Wikipedia [1] it was the first time you could play the predecessor game in a newer version.
The whole original Maniac Mansion game can be played on a
computer resembling a Commodore 64 inside the Day of the Tentacle
game; this practice has since been repeated by other game
developers, but at the time of Day of the Tentacle's release, it
was unprecedented.
[1] https://en.wikipedia.org/wiki/Day_of_the_Tentacle