Ooh, that's a super unique mechanic that feels really nice to play with. Also just a great use of the theme. I like how it drops the player into things, so I made an automatic assumption that I was avoiding death. The realization that dying was actually a game mechanic was a pretty freaking cool moment.
As is to be expected of a jam game, this could use some polish. The combat is pretty lackluster; although the possession mechanic fortunately makes up for this somewhat. While the art as it is works just fine, if you have plans to expand on this, obviously things like animations, some feedback in the attacks and getting damaged, and stuff like that would be quite nice. But again, I imagine all of this is due to time constraints. I think overall, you probably focused on the right thing (the possession mechanic)!
Overall, just a cool experience. I'd love to see this expanded, or at least more of the mechanic. I think you could end up with some fascinating puzzles. Great work!