I liked this game it was creepy. I would add and tweak somethings.
A screen, that shows the controls before you start the game, or just as you enter the game. The controls for opening doors are different, to the collect doll controls. I only figured out the button, by randomly pressing buttons on my keyboard.
The Grim Reaper himself, wasn't really a threat until I was close to the end, after collecting all the dolls. Apart from that, I didn't really notice a difference in the speed, the Grim Reaper moved as I collected the dolls.
Hope you continue to make games, I will be sure to follow you, and play any games you do make in the future 👍