There are 2 multiballs in the game so far:
* Triple Knights challenge (3 ball) from 3 locks at the shield
* Black Knight retro mode MB (3 ball) from spelling the KNIGHT letters.
So far it looks like the only way to get the 6 ball MB is with the LE/premium. Maybe that will change.
Quoted from newpinbin:
Seems there is only one multiball in this game. Which is a three ball multiball, plus one add a ball for a total of four balls. The game holds six balls. Am I missing something?