Wonderfully atmospheric!
The audio is great throughout, really adding to the tension that never lets up, and the theme song during the title screen is fantastic. Loved that low, growling John Carpenter-esque bass!
Loved the cryptic placement of the keys, definitely reminiscent of early Silent Hill and Resident Evil titles with the almost surreal methods used to find them :)
The transition to the second level is a brilliant change of pace, I hadn't looked at the screenshots before playing so was not ready for that! All leads into a really strong ending that works perfectly with the hints dropped via the notes.
Had a great time playing :)