Creating Atmosphere
Not every moment needs a catchy melody or a dramatic swell - some of the most important work music does is set the tone between the big moments. It will also help set the aesthetic of your production more intentionally - a classically gothic horror score will lean into the over-the-top fun of the show.
Though the instruments involved in your series would be different, the kind of energy and tension of this track of mine is a good example of setting the mood without taking attention away from the rest of the content.
Setting a Winning Pace
With long-form content like this series, keeping the energy up across nearly 2 hours of content can be daunting. Something I've found that helps viewers maintain a sense of momentum is strong segments like the ones you've already incorporated into your first two episodes!
To add to this effect, I'd love to extend each "Night" music cue a little, playing under your narration of the activities from the players that night. In addition, I think it might help add to the intensity of the late game by turning up the spookiness-dial a little more each night, so by the final night we have a fully-horrific version of our "next night" music cue.
Below is an interesting, pace-setting piece I composed for a short film with a strong theme that could be manipulated in such a way.
Creating Familiarity with Themes
Because this miniseries will feature several recurring roles and events, we should craft specific motifs for these aspects of the game. That way, viewers can feel each episode is connected, even though each game will play out differently.
For instance, each time the IMP role is revealed, or makes a meaningful move during the game, we can build familiarity with the actions of past imps and the game at large by playing a recurring theme that can build over time, and shift to fit the mood of the scene. Below is a track that I could see being used to build up the impact of a big moment - like when Xander decided to kill himself as the imp during episode 1!