Really cool puzzle! It took me a while to understand it. I read the tutorial but hovering over the signs just went over my head as I started playing. I got to room 6 without seeing any ghost and died because of shooting at nothing!
I really liked the tense feeling the audio provides! The song is so subtle yet so tense! The shotgun sounds and the ghost jumpscare are very good too.
Visually it is very charming, the girl and the ghosts are rather cute. The animation for the ghost killing you was a surprise!
After returning to the tutorial and reading once again, I got the hang of it. Very interesting way of arranging the ghosts. Only complaint I got there was one my last runs ended because a ghost spawned RIGHT at the last tile, and I had to go up to it, there was no way to shoot that ghost. Perhaps being able to control shooting direction could solve that!
I'm probably nitpicking, but I felt the death animation could be a tad shorter. As soon as a ghost killed me I started clicking the mouse to try again and it would take a while (nice touch with the tombstone by the way!) before I could.
Congratulations on making such an interesting puzzle!