With the addition of ambient sound to the Doom engine, Heretic has an extra dimension of eeriness to accompany the Dark Fantasy theme of the game.
As usual, Spoilers Off apply to all moment pages, so proceed with caution if you don't want to spoil impact of the nightmares described below. You Have Been Warned.
- E1M9: The Graveyard, is a pretty Bleak Level, and relatively dangerous Secret Level with its sheer number of Undead Warrior Ghosts. The fact that it's explicitly a place where remains are buried can be a step up in eerieness from the game's spiritual predecessor, Doom.
- E4M9: Mausoleum, is like a sequel of sorts to the aforementioned Graveyard, using the same dire soundtrack. This time, you're completely underground, albeit in a mostly constructed artifice, with no sign of the surface sky. The lighting is very unreliable here too, and progressing requires some guesswork.
- The Iron Liches have an eeriness to them due to their realistic texturing. They're like a robotic giant skull with a helmet and have a constant Slasher Smile to them. Their appearance at the end of Episode 1 can be jarring after getting used to the relatively normal monster Mooks. Their attacks also hit like a truck. Their screams they make sound like a distortion of someone crying out in agony, plus this sound is also used as level ambiance, creating the sense you can hear one crying out in the distance.
- The Disciples of D'Sparil evoke a sense of Nothing Is Scarier with the hooded cloaks concealing their face so you can't know what they look like. Their phrases they chant are actually English phrases reversed: "Destroy the Heretic." and "Succumb to us, Heretic." which makes it sound like they're whispering Black Speech. Like most enemies, they collapse into the pile of giblets with a sound vaguely like they're choking on their own blood.
