$6055 checks for <ESC> (ends demo, starts game)
$60FD checks for Ctrl-S (changes sound once game starts, but sound is always off during demo) (harmless, ignore)
$AB43 is after demo cycle (demo player has died and returned to spawn point) [7 bytes available]

$6055: C91BD011A20D -> AD88C06CFCFF to exit when user presses any key
$AB43: A90085614C49 -> AD88C06CFCFF to exit after demo player has died and returned to spawn
$6021: FF -> BF to reduce time before demo starts
