Nice and simple concept :)
Although you should put controls somewhere on your page. I had no idea how to pass doors on tutorials ( owo") .
Also Camera rotation with the mouse is really slow. I guess it depends of the computer maybe or each person mouse sensitivity :D .
I'm not sure if it's intended but for some levels the Instinct bar deplete way before you could even pass through an enemy, or doing the back and forth to exit door.