The earliest I can recall for sure was a simple drawing program on
an early Apple in BASIC. You used the arrow keys to move, the
space bar to toggle from "draw" to "move", and the number
keys to change the color.
I had some sort of earlier computer too, I think it was a
Sinclair something (??) and I know I wrote some programs
on that, but the only thing I can remember is that you
actually stored your files on a regular audio tape, with
a normal tape player, by audio and microphone extension jacks.
You could actually listen to your programs (resembled the
well-known "modem connect" noise, but had a distinct
difference).
After a while, I managed to write one of those adventure
games as well. I don't know how I managed to do all that
string parsing ("DROP THE BOX", "KILL TROLL", "LIGHT
THE LANTERN") and everything else involved in a language
other than Perl. Where was Larry? :) So much spaghetti
produced for so little output.