when you beat tuber you get a star, with it you can start playing nightmare mode. In nightmare mode the fruits start like if they were already in quick mode and you have

all the time.
And there's even more, when you reach lvl 50 and kill the pears you get a key like the one in the fist message of the post to enter the dimension of lvl 82 (we need the update for that) and if you beat tuber you get the "nighmare key" (nightmare modee) I'm not really sure where it could be used but we need the update.
PD:I can't see any difference in the time that the fireball takes to appear