I am not sure if there was more to the game than I found!
I had the choice to explore, which meant I found either nothing, despair, or hope. These effected my amount of ennui. Energy was also consumed each time I explored. I could regain energy by resting, but ennui still went up. Being idle had seemingly no effect.
Both of my explorers died to maxing out ennui :( I didn't find anything other than hope, despair or nothing :(