My first "real" game (in the sense that you could play it and accumulate score) was a game called "Submarine Panic" that I wrote in the TI-99 4a when I was ~11 years old.
In this game, you controlled a submarine sprite with the joystick. There were constantly moving sea monsters (each constantly moving in a single direction that wrapped at the edge of the screen). Your goal was to avoid them for as long as possible... and the score ticked ever upward until you died.
The sequel to this game was called "Asteroid Panic" which may have been one of the world's first "sequel that's just a reskin"... but because it was exactly the same game only with a black instead of blue background... and instead of a submarine, you controlled a lunar module looking thing... and instead of sea monsters there were... wait for it... asteroids.
Naming my ES example "Asteroid Panic" was a subtle homage to that old game I wrote so long ago.
Both games were stored on a cassette tape (yes, that's really how we stored data once)... that has since been lost to history.