Guillermo Del Toro uses horror-movie tropes to set an atmosphere that is frightening, but not too frightening. A door swinging shut, a grotesque doll, a ghost child: they're less vehicles of fear than a vernacular of suspensefulness with which to tell a story of maternal loss and devotion.
One unusually graphic scene, involving a torn-open mouth, echoes the sliced-open cheek of the Republican general from Pan's Labyrinth. Like The Orphanage and its horrors, Labyrinth used stock -- though beautiful, poignant -- pieces of fantasy in the service of a genre-independent tale. At the end of each, a question lingers: was it real? Or imagined? And it doesn't really matter.
As an aside, while Orphanage wasn't too frightening, it had its moments. And just to clarify, reclining in a seat, knees pulled to chin, chewing on a hat and going "aaaaahhh!" is actually the basic fighting stance of an ancient half-Filipino martial art, kinda like karate's kiba dachi.