Really cute idea. Having a popups for controls, like the possession/un-possession and getting through doors would have have been helpful. I think it would have been nice to have the dossier pop up for whoever will o' wisp was facing so you didn't have to possess everybody for the initial intel gathering (and had more contrast to be easier to read). Also the doors took a few clicks to get through.
The writing was really fun, swamp is pretty spicy! The music choice was great too, good work!