When the engineer is away, the machines will play. Machines that you aren't standing near or looking at will slow down to a crawl over time.
Small changes concerning balance, gameplay, or graphics.
Changes to the player's in-game appearance.
New Ores and resources as well as machines.
Furnaces, assembling machines, production chains.
I am wondering what made you think of this idea, its weird, yet makes sense in a way only someone with a cractorio addiction who stayed up all night would understand.