Microsoft used to include easter eggs in their programs, but stopped in 2002 as part of the "trusted computer initiative". [1] Excel 97 had a hidden flight simulator, Word 97 had a hidden pinball game, Access 97 and 00 had a magic 8 ball simulator. Office 4.3/95/97 had a hidden Doom-like gamed called "The Hall of Tortured Souls". There is also a car driving game in Excel 2000.
[1] https://en.wikipedia.org/wiki/Easter_eggs_in_Microsoft_produ...