I was thinking the game could be about etablishing temporary alliances with the other murderers in order to survive. As for items and stats the only things I think should be included is food(a hunger system for all characters, and hunger impacts the NPCs too, knives and guns. The characters would have a personality and a relationship system to the player so that the player can form alliances depending on their needs. Due to the complexity of narrative I was willing to drastically sacrifice graphics if it comes with more time to work on dialogue and complex systems to make it so no two runs are the same since you can betray everyone and everyone can betray you.
To ease comunication here is my discord: shadejay12