I enjoyed this short visual novel. The art style and the slow dramatic tensions was masterfully implemented into this game. Although, I had a subtle feeling that it was him who killed her at the start.
Possibly, before the puzzle of the select 5 items you can touch, feel and hear you can add like loud thuds at the door and fake dialogue to create the illusion that the killer is there but then realise that was all internal manic thoughts once the girl appears.
I loved the ending where it had the movie like flashbacks and camera zoom ins. However, I do not know but is the ending just a still image of him. I love visual novels and from my experience this was a very well written and drawn visual novel 10/10