I love stealth game and I think there is not enough of it. Thanks for making one!
I have some problems with your entry though:
- when possessing a guard, the field of view becomes so limited it's close to unplayable in large levels
- you need to get close to possess, but guards find you when you're close, which leads to weird situation where I didn't know if I was going to successfully possess or get caught
- tight corridors in "stairs" shape are a pain to go through