Interesting tidbits here:
https://www.arcade-history.com/?page=detail&id=320
Like us old farts would be good enough players to succeed in this:
"Bonus for no-miss clear (completing a round without dying) - this bonus is given only when the game is set to auto difficulty : multiplier x number of bases, the multiplier starts at 100 points and increases by 100 points each time you get the bonus up to 1,000 points."