Personal Nightmare is a survival horror adventure game that runs on Amiga, Atari ST and DOS. The DOS version can only make use of EGA Graphics. There is no direct plot, but the game focuses on a town where The Devil has invaded and the player has four days to eliminate all possessed citizens and purge the evil before it can take over.
The game makes use of a combination of text-based commands, clickable verbal commands and clickable objects to progress. A compass indicates which directions the player can travel. Much of the game's movement and actions are real time based so there is a day and night cycle. The player's inventory can be viewed in the respective menu. There are many encounters that can kill the player (ideally at night time) unless the player performs a proper action to avoid them. Newer versions of the game omitted the encounters where the players gets garroted. The player loses the game if four days pass and all the required possessed citizens have not been killed and the devil has not been repelled.