In 1998 Assembly programmers who typically participated in Demo competitions did a series of size coding challenges. The first one was a Snake game (Nibbles), all in a DOS environment. The winning entry was 48 bytes long.

https://hugi.scene.org/compo/compoold.htm#compo1

There were also some creative attempts that took less than 48 bytes and got disqualified. One of those encode the entire game in a series of empty folders using the folder names.

Edit: the original Hugo size coding competitions were created by Claus-Dieter Volko (Alias: Adok).

Edit: Typos