So Prom Night, featuring the stone-faced intensity of yes-he-really-spells-his-name-like-that killer Johnathon Schaech and the umm, much more interesting assets of Brittany Snow, isn’t screening for critics, apart from a come-and-get-it-if-you-want-it 10 a.m. “courtesy screening” this morning, its day of release. What a shock, really. This is the new confirmed writ-in-stone trend for PG-13 horror flicks.