From the Designer's Website:
Jouez un revenant, et protégez la frontière entre la vie et la mort...
User Translation from French:
Play a spirit of the dead, and protect the border between life and death...
("Les fleuves de l'enfer" is French for "The rivers of hell".)
Characters have four points to split between life (and for each point they list an affinity) and death (and for each point they name a river of hell).
To perform an action, the player rolls as many six-sided dice as their life attribute, keeping the highest roll. This value is reduced by one if the character does not have an appropriate affinity. The result is compared against a target difficulty or opponent's roll.
To use a supernatural ability, the player rolls as many six-sided dice as their death attribute (and resolves as per normal actions). Each river aspect grants different powers.