They could use the staircase, the bathroom, the bed, and the wall with the phone as separate pieces, but after that they might have to break it up a bit. Maybe some cheap jump scares where you walk by the freezer and the kid is rattling the door. Or they can use the Super 8 style dream sequences that end with the ghosts of the kids startling you. Maybe use a scene with the van at night where the headlights or the engine surprises you. But they definitely need the creepy voices on the phone and the Grabber with the balloons.