Loved the art and atmosphere, and whole possession-on-kill mechanic was great.
A few bits of constructive criticism.
- The lights seemed to rotate slower than the player, causing a disconnect. As the sprite change is instant, I'd just instantly snap the light, rather than smoothly rotating it.
- The player's health is unclear.
- The difficulty was a little high. Perhaps checkpoints would help?
- I wasn't entirely sold on the aiming. Perhaps mouse-aim would have been better?
- You'll get far more reviews if you build to webGl, rather than having a download.
Overall, great job!