Always an honor to be the first to comment. Superfly is not one but two games filed under different names "Superfly 1k" and "Superfly 1k+". The "1k" in their names is a declaration that their file lengths are 1 KiloByte code+data size. Both games work best in PAL video, from having been made in Germany. See also the game "Fireball 1K". In the game "Bell Jumper 1K" the controls didn't work for me.
1k and 1k+ have different gameplay, but I see no reason to say the + game is "update, improved, enhanced". If anything, the + game is a downgrade for being one byte larger. "Superfly 1k" is 1022, "Superfly 1k+" is 1023, and because the unimplied goal actually is a cool game within the smallest possible framework, "Superfly 1k" is an enhanced remake of the "1k+" game :^) ... some more cool games that happen to be TINY, Syntron 1992, Fighter Pilot, Mahna-Malysz 3369, "Planetary Defense" 3522.