Not usually a horror fan, but turn it into a card game? I'm listening.
I really like the concept having space be a sort of stand in for the typical mana system that you'd see in other card games. Playing cards also kinda reminds me of inventory management in Diablo 2 which I personally really enjoy, and the phrase "GET INK" to play cards goes real hard. Hiding the mouse cursor during movement sections in between fights could also help sell the immersive effect really well given the solid quality of your environments. Awesome stuff!