Circa 1985 in our school BBC Micro lab, we wasted much time playing a tiny type-in game that looked a bit like this:
The playfield was filled with a random arrangement of asterisks, and the player controlled a continuously-growing diagonal line that could be switch from falling down to going up by pressing a key. The game played similarly to later games like SFCave (Palm) and Flappy Bird, except the screen didn't scroll. There were ports to other systems, such as one to the Dragon 32 (written by Alan Cook) and another to the Amstrad CPC (written by me, published in Amstrad Computer User in 1988).
I'm trying to find the original. Here's all I know:
It was written in BBC BASIC
It was most likely called "One Line", but I have a faint memory of it perhaps being called "Whirly"
It was one — quite long — line of BASIC
It was most likely published in a UK computer magazine such as BEEBUG, The Micro User, Acorn User, etc
The BBC version may not have been the original, as all the game required was a bitmapped screen and a single control key.