Kudos for attempting voice acting, I think that was an ambitious goal to pull off and y'all managed to get it implemented. It goes a long way in cluing us into what's going on in the game. The dialog itself is a touch clunky at points, but it's very serviceable and I like its inclusion.
The map itself feels very abstract. I think this works for and against the game. Feeling like you are in a space that doesn't make a whole lot of sense and is hard to navigate can add a lot to a creepy tone, but I'm also left wondering what about this space is supposed to look like a sanitorium beyond some props in a couple of rooms. Its extremely dark and almost feels devoid of lighting. That works for the horror since I felt like I was seeing things in the darkness, but also leaves the game lacking in aesthetic quality.
Your ghost is incredibly creepy. I think this is helped immensely by the sound design. The reverb-y ambiance works incredibly well, and hearing your ghost's voice in that ambiance leaves me with a lot of dread while playing. If there was anything I would change, it's the hard cut when the audio restarts. Having a seamless loop would make the suspense feel just a little more real, and give me fewer reminders I'm playing a video game. As for the visual component, I'm shocked at how effective her pose is for creating scares (trying not to be too specific so I'm not spoiling anything). There's something about it that feels just uncanny enough that it's terrifying to see come out of the darkness.
Overall, nice submission. I think you all did a good job in the time allotted.