"13B" is a new form of horror movie where they don't show ugly disfigured faces painted with blood (tomato sauce) or ghosts moving around to kill anyone they wish. Especially the scenes of the elevator not moving up when Madhavan boards it , or the TV serial in a particular home showing a different story than elsewhere, are pretty original in treatment in hindi movies.
Nevertheless, the idea of ghosts coming to kill Sachin with a hammer is poorly scripted and brings fun rather than fear. Madhavan's performance is the USP of this movie. Wonder why Dhritiman Chatterjee, such an astounding actor in Satyajit Ray's films, decided to do this no impact role of the blind old man.