I got the Squee sound effect from here https://www.youtube.com/watch?v=88vkDp6vI0I
Note I modified the game to remove the watermark although I am not really into creepypastas and avoid stuff with jump scares on my channel so I have added a version with the jumpscare as an unlisted video here in the description to avoid someone with YouTube autoplay on getting the shock of their life. Unlisted video here https://youtu.be/EqwLvXTaX_M