I smirked at the name of the institution, really silly but fitting!
The soundtrack is a bit repetitive but worked wonders for the tension built. I was just curious, sometimes there would be some wailing/haunting sounds, was that random or there was some relation with the creature approaching?
Visually it felt very cohese. The creature was damn creepy with that bizarre smile, well done!
I really liked your take on the vacuuming souls mechanic, it really made the ghosts feel like they were being sucked in.
Were the ghosts spawning only after other ghosts were vacuumed? I spent a long time running through the upper part of the map for nothing, then found some ghosts at the bottom. Once I got a ghost, another appeared nearby. Also, did the creature disappear sometimes? 'Cause when it got close I ran from it but as I got ammo I made my path back and it just wasn't there. Perhaps it could have been stuck at some collider?
Also, regarding colliders, going through corridors worked very well. I just had one time that a ghost seemed to go through the creature, I shot it from the torso up, but it just passed through. It was the only occasion though!
The tutorial went alright for the most part, I just wish the letters would appear faster. Or perhaps you could implement a way to skip the text appearing, as in, press space to make this whole section of the dialog appear. I liked the dialog but it just felt too slow.
All in all, great atmospheric shooter you got there!