What worked:
The atmosphere was good. The music added to this atmosphere. Leading the monster around and manipulating where it went felt good.
What didn't:
The lack of checkpoints hurts the game since it takes a while to get through it again, especially when you die after collecting the 5 candlesticks. The game feels too long, physically. There are large portions where nothing is really happening and you're just walking down a corridor. It might be better to have shorter halls but more intense gameplay.
Bugs:
Didn't see any.
Great job!