Honest the idea of a masked killer with one of those horse masks sounds terrifying lol if I was in the middle of the woods and a dude comes at me with one of those I am running for my life. 
It does needs polishing, but for a 6hrs game I think it could be considered a good beta. 
I think my main observation is that it felt a bit on the edge of serious horror or being farcical, I'd say go full farce, embrace the absurdity like those horror movies that make no sense and it's just lots of blood and deaths. 
Also if you are into visual novels, I recommend trying TyranoBuilder, there aren't many tutorials in English, but it's very easy to learn (coming from someone who only knows how to use RPGM). It's as easy as RPGM or more, and has a lot of easy, already programmed options for visual novels. 
Sorry for the novel, I love talking game design.