You can get through without killing anyone, but it's frustrating. What I believe is downright impossible is killing EVERYONE. I managed to kill 22 (8 scared off) once, I wonder if anyone has gotten more?
I love this little game, but turtleslayer5746 is right on. The reactions make no sense. The bathtub is dancing around in the air? This makes me somewhat nervous. Some plates fell? Better commit suicide.