This is definitely a good start. I think sound design-wise, it did well enough to create a creepy atmosphere.
I wasn't able to complete the game due to a couple bugs. First was when I was in the Parent's room. I walked to the right and fell off into the void.
After restarting, I got further, but got to a point downstairs where the darkness engulfed me. It tried to reload me by my last checkpoint but every time it did I was immediately engulfed by the darkness again making it stuck in a loop.
As far as gameplay goes, perhaps this is from only 15 minutes or so of playing, but I felt that the battery in the flashlight goes out way too fast. I tried to use it conservatively to ward off enemies but by doing that I got killed by the darkness. Alternatively, when I was using it, I found that my battery burnt through so fast that I didn't really have it for enemies or to traverse the downstairs anyway. Although, again, take the time put into the demo into account when looking at this criticism as it may not be entirely accurate. Was just the feeling I had.
Anyway, I think this is a great start. I really like the concept. It reminds me of Among the Sleep which followed a similar concept of a child experiencing horror and how it might be rationalized in there head. I'll definitely be following the project and will check back in another update or two!