Replayability seems to have been one of Pajamas Soft's main goals with Prism Ark, cause I just started my third run with Fel's arc, and there's even more new stuff going on!
What makes these things even more interesting is that they make it almost seem as if the protagonist, Hyaweh, had gained some sort of pre-knowledge of those things. Like how something used to happen over and over in the first two arcs, so the protagonist then does something that prevents it from happening again in the third.
My first thought upon seeing this happen again was, "Higurashi!"
Of course, without the horror and psycho girls.
(PS: Onigiri bombs!
)