I discovered this a few years ago playing Ultima IV on my Amiga 3000, which is 16Mhz. It was impossible to play (and funny to look at) because the game was so sped up. All of the NPCs in the game, which normally just stand in place and move their arms about, were moving so fast it was bananas. You could barely see their arms they were like hummingbirds.

The game was intended to be on a 7Mhz stock machine pre-1990. And it was perfectly timed to that speed.