This is a cool concept! I definitely had trouble figuring out the possession mechanic. I played until i got to the second door i needed to possess an enemy to open and I couldn't progress because I had accidentally killed the enemies. Too easy to accidentally kill enemies.
My main feedback is that the "actions per turn" and associated reset delay makes the game feel unresponsive and clunky. I also gave you 4/5 stars on music because it would have been really nice if the music was seamless instead of restarting each level.
I liked it overall, great job!