The music and sound effects all really worked together well to make it scary. The part where you enter the house and are trying to find the other person, was genuinely a terrifying time, the darkness, the sounds, they all made it so scary!
The only place where I would say that the game could have been better are the story itself and also the scares and beginning part. Starting off with the beginning part; I think finding the way forward was a tad bit confusing as there was no direct path or anything guiding the player on where to go. Also going all the way back to the car and then all the way back to the house felt like it took away from the scare; could have added more scares or something more than just the rabbit part to keep that tension constant.
The second thing was that the first part of the house felt very underutilised; there could have been scares fitted in there. Especially on how the camera movement while looking at the items was, it could have been incredibly scary.
Then the third part of the game gives the majority of the story, which wasn't paced very well and while it's a pretty cool story with a fun and interesting twist, it doesn't pace it well and there wasn't enough subtle connections from the beginning that gave the ending the punch that it deserves.
The above are just my thoughts on how some small things could be improved, but overall, it was a pretty neat game with great implemented ambiance and environments and sounds! A fun little horror experience!