Fun game, scores off the charts for atmosphere and mood. I was quite tense playing it!
I don't know if it was my method/approach but the outside bit seemed a lot easier than when I got in. The outside death reaper guys just did not seem all that perceptive. But maybe I was just good at avoiding them. Maybe if you continue this game further, add some visual elements around stealth detection etc. Check out GMTK's recent video series on stealth game elements.
Impressive work with the stereo creepy voices!
A small suggestion? maybe have savepoints? So that we don't get scared again and again when replaying the same bits? ;)