Brilliant atmosphere and music. I love the film-like opening.
I never get far because once you're seen it tends to be over in seconds. I don't like to replay because it ruins the idea of only having one life. So it is quickly panicky, but that can leave you running around like a speeded-up comedy skit. If the danger was toned down _slightly_ I'd probably get further with it as a game, and experience more tension overall!