Really impressive game liked the gameplay though I did kill the npc's since they kept following me popping up text so when it reached 6+ nothing happened not sure if that is just what the ending is or if me killing the npc's messed it up. Really nice list of spells and glad the enemies improved along the way as well, helped keep the game fun and kept me engaged wondering what the next spell I'll get will be and what new enemy will appear. Few things I'm unsure about is the spells sometimes just went through the enemies only seemed to get consecutive shots off if I made sure to get head shots or right in the middle of their chests. The fence in the middle of the map was only collidable on the side the gate was on all the other sides you just went through which was a bit odd, and I was pretty lost overall on what I was supposed to be doing the stones kind of just told me to kill stuff so I did and then nothing really ended up happening after 6 again if it is because of me killing the npc's my bad ignore my comments about the end. Though I do feel some more direction would be helpful. My final comment is in the theme as someone has already mentioned it doesn't really fit the horror theme it is more fantasy action adventure if anything.
There were a couple other things I might change but they were minor like having spells already obtained not drop but nothing major the ones listed were the big things that I came up with while playing it. Hope some of this is helpful feedback something akin to what you were looking for. Had a fun time playing your game specially in the variety of spells, well done.