'A Machine for Pigs' is an indirect sequel to 'The Dark Descent.'

The game design and style are similar to 'Penumbra: Black Plague.'

Work on the game began while 'Penumbra: Requiem' was being developed.

'The Haunting' also inspired the game’s mood and style.

The 'Justine' DLC was released to promote the release of 'Portal 2.'