Wobbler had written an actual computer game like this once. It was called
"Journey to Alpha Centauri". It was a screen with some dots on it.
Because, he said, it happened in *real time*, which no-one had ever heard
of until computers. He'd seen on TV that it took three thousand years to
get to Alpha Centauri. He had written it so that if anyone kept their
computer on for three thousand years, they'd be rewarded by a little dot
appearing in the middle of the screen, and then a message saying, "Welcome
to Alpha Centauri. Now go home."
(Only You Can Save Mankind)
--[discworld]--