Thanks a lot for your comment!
Your theory is interesting! We don't know what happened to the girl before she took that train. Is she still alive? What happened with her boyfriend? All we can do is guess...
At least we can tell you about the huge face: it's inspired by the Japanese Noh masks. here is a picture
We'll probably do more yôkai themed horror game at some point. We loved making this one in collaboration with students but now we want to make another one with our own art. But we have to finish The Coral Cave first (it is also about yôkai but less horror).