I think this has potential; a lot of it. It looks great, and there are little details that make the house feel lived in. I especially enjoyed the themed keys a la Resident Evil. I also enjoyed the puzzles; nothing too easy or too difficult, but enjoyable enough to remain engaged.
Given that this is a prototype, it’s hard to fault it, but assuming you go forward, a few suggestions to smooth out gameplay. Some may disagree, but it’s too difficult for me to engage in a story told through notes if the text is too small to read. In addition, unless there is a gameplay reason for clicking on doors twice, I’d remove it. Since it’s so early, there may be a good reason to only partially open doors, but as it is, it only served to slow gameplay down.
I was hoping for more horror, but there was one moment in the prototype that made me a bit nervous. If you turn this into a game, I think your ideas on how to spook the player will serve your game well.