According to a blurb in the November 1989 issue of Cinefantastique, director David Irving assembled several different versions of the film: one highlighting the comedy, one emphasizing the horror, and a third cut explicitly for television.
Despite the poster having the creatures (CHUDs) looking the same from the first film and being right at a manhole cover, they are actually different looking zombies and there is no sewer involvement throughout the film.
Was originally conceived as a sequel to Return of the Living Dead.