I am late to the party here, but great job on this game!
Firstly, I have found the mechanics to work wonderfully -- I haven't found any bugs during my playtime. Finding the switches/pressure plates was satisfying, and the tension made it more rewarding.
As a horror enjoyer I may be biased, but I loved the feeling of tension throughout the levels, especially the last one with two geists!
The game does a good job on respecting its theme, and I was happy to see that dying would let me respawn on the same level with the same progress.
If I may suggest one thing, I would make the geists disappear for a short while after expelling them with CTRL, as in the last level I kinda got into a situation where the leftmost geist would get temporarily expelled, then it would simply wonder left by a couple of blocks, and then it was immediately ready to attack me again!
But this did not hinder the experience: since that was the last level, some challenge was expected.
Definitely great job on this one, I hope to see this idea get more expanded in the future! (7 deaths here)