Terror en Amityville

Saw this on a VHS in the mid 80s. Revisited it recently on a DVD. To be honest, i found the movie to be tedious n tame then. Now i jus forwarded some boring scenes. The film opens on a dark and stormy night as we hear gunshots and see flashes of light through the home's famous eye-like upstairs windows as an entire family is killed. A new family moves in after a year n unsettling things begin to occur. Ther are scenes where the walls drip blood. Was it blood or tar i don't know. Whose blood it was or where it came from was never explained. There's a hidden room in the house the dog always barks at. In one scene James Brolin climbs the stairs above that room, only to fall through them and into a pit of the same blood/tar. Was that suppose to be comedic? Also the scene involving Rod Steiger with the flies wasn't scary at all. The movie was boring considering the length n nothing happens. Somewhere around 01.16, Josh Brolin breaks open a wall n his facial expressions n eyes r epic scene man. What he sees that makes him so startled, we never come to know n we don't get to see also. The film is helped by an extremely creepy score composed by Lalo Schifrin n Brolin delivered a good performance. Margot Kidder did a decent job.