here's some info that was said in the livestream
HHN - Orlando: "EXCLUSIVE: behind the scenes round table for #HHN28." . sorry if some are old news again.
strangers things - waffles will be there, gonna see the demogorgon a lot throughout the house, the forest is gonna have mirrors on the walls to make it larger along with mirkwood signs, "in mirkwood, we've done a audio trigger that is gonna relayed later on in the maze, but it tells the same story, but because characters are in difference of space having being recorded further away from each other, you actually get a sense of travel between the characters".
poltergeist - you're gonna feel the ghostly presence,
seeds of extinction - several camouflage scares in the house, one location in the house is a convenient store.
killer klowns - map projection will be used in the zone for shadow puppets , ice cream truck with jumbo on top will be there,on the walls will be the ship and throughout the night the tent will lift up [projection they said], klowns will be huge, popcorn creatures will be there.
revenge of chucky - chucky will be a live puppet, couple of characters from the 09 house will be in the zone.