The City of The Damned - Apocalypse is a 2011 PWAD made by Tormentor667 as a sequel to his another Wad, The City of The Damned, althrough loosely connected to it.
Plot[]
The mod takes place during 1920's. A cult known as Darkmoon decides to unleash a demon named Thamuz and hordes of other hellish creatures on a small city. A siren was installed to inform citizens about especially malicious monsters that come out when it sounds, and a shelter is only way to escape them.
Player goes around the city, killing cultists, demons and ghosts and has to collect three artifacts in order to summon Thamuz and kill him. Afterwards he escapes the City, and the mod hints at a possible sequel, with the citizens stating at the end that "for us, the day of reckoning has merely been postponed".
Description[]
Like its predecessor, It uses many Blood resources, including textures, weapons, and monsters from the game. ACS scripting is also used somewhat heavily to produce several puzzles and a significant storyline. Music is taken from various horror games, mainly Resident Evil 3. A neat element to the story is added to the gameplay where a siren periodically goes off and you are forced to dash for specially marked cellars. If you can't make it to the shelter in time, the beforementioned monsters, refered to as "nightmares" come to kill you.

The starting area.
The game includes ACS-made notes for the player to read. Avaliable equipment includes pitchfork, an Anaconda revolver, Thompson machinegun, a sawed-off shotgun and a napalm launcher. The look of final boss is determined if player chooeses "Path of Blood" or "Road of Doom" to walk out of the beggining area. If the Path of Blood is chosen, Thamuz looks like a recolored Cyberdemon. If Road of Doom is chosen, he will resemble a recolored Chernobog from Blood.
Reception[]
TCoTD - Apocalypse was praised for its extreme attention to detail and dark creepy atmosphere. It was criticized however for the gameplay. Many found it too hard or frustrating due to the amount of keys you had to find, lack of ammunition/health and tough monsters. Some of the puzzles while unique were confusing for some players. Overall TCoTD - Apocalypse received mixed comments and reviews.