I am going to keep leveling up throughout the event because there aren't any event character tasks so why not
I think 20 is where you stop getting hats as a reward for upgrading.
I don't really see the point in this. The tap radius doesn't seem to be such an issue when they merry makers are so sporadic and easy to find/tap
I don't plan to stop until the event ends, another event task requires all of those characters, or I reach a level where one thunderous tap extinguishes all merry makers throughout the universe.
It looks like you're new here. If you want to get involved, click one of these buttons!