Shoot-'Em-Ups

I have finally noticed that I read comics in two modes: one for Persepolis and Vogelein, and another for Birds of Prey and 52. The latter serve for me the function Ace Double Novels did for my father (what he referred to as "shoot-'em-ups"). I think other people establish these categories early in life, often discarding one or the other entirely. Not sure what that means, either the division or the timing, but it's something I have noticed. //The Magic Eight-Ball says, "A rolling stone gathers momentum."\\