Repeating my comment on the playthrough: I think this is easily your best game so far. I do have to agree with CJU on the threat level though. There ought to be more places to hide, and Edith (and Daniel) should be more of a threat. Maybe you could add a difficulty setting to compromise? If it's a player progress issue, you could always set checkpoints each time they solve a puzzle. That aside, this really looks good, great atmosphere....

Picked the book up out of the chest connected to the 4 mask puzzle and then got killed. Book returned to the chest but it became completely non-interactable and unable to be collected, rendering the game unable to be completed.

:D