IBM spent a humongous amount of man hours upon the running man in smit under AIX, many of those consumed with making sure it ran correctly on all systems of various speeds without the animations going crazy. Alas I don't have exact man hours, but that was what one of the engineers told me a nearly 2 decades ago now. Hopefully somebody else has more detail upon this as one of the earliest examples of progress animations that still runs today that I'm aware of.

I still hark back to the days of the C64 and the likes in which had tape storage and was common to have a game as a loading screen to play. Was a small program and used to give the user something to do whilst they waited 20 minutes for the program to load. Many also rewrote the cassette storage code for faster storage/loading and would often be a case of loading that program with the small game like space invaders that you could play whilst the main game loaded utilising the quicker tape handling code.