Gauntlet by Donald R. Lebeau, 1984 (forums.atariage.com)

A forum thread about an obscure Atari 800 shareware game and the search for the registered version that was presumed lost. The developer appears and gives a lesson on 6502 game engine programming techniques - and the harsh realities of the shareware market in 1985.

This was known as gauntletak. Not the 4 person super hit of the same name. Wikipedia for this: https://en.wikipedia.org/wiki/Gauntletak