Two cutscenes appear on the CD but not in the game. One of them is a video the player is supposed to see upon entering The Butcher's lair, and the other one is of Diablo gaining power if the player fails the (never implemented) Map of Stars quest.
They should of included that... oh how they should of included it... i mean!!! jesus!!! why not!!! argh!!!
Blizzard isnt known for making mistakes but not finishing that cinematic and not including it in Diablo1 was a mistake