Long Dark Sea: Dark Side Expansion

The Dark Side Game Mode introduces 52 alternative copies of enemies, locations and events with the dark back cards to make even more difficult and unpredictable the core game.
The dark back card mechanic makes the game more unpredictable because you don’t know what are in the other side of the card and also makes the enemies more hard because they are affected by eclipses on the Luminara System.
This expansion is designed for those who are not afraid of the dark.

—description from the designer