“Skinamarink,” the runaway success story of the moment, is at once the stuff of literal nightmares and every indie filmmaker’s dream: a $15,000 chiller that’s earned $1.8 million in theaters in a matter of weeks. And, love it or hate it, polarizing reactions have made writer-director Kyle Edward Ball’s experimental debut feature — in which two young siblings wake up in the middle of the night to find their father gone, the doors and windows missing and a malevolent entity in the shadows — cinema’s latest word-of-mouth sensation.
