Hey dude, this is a great demo! A few things about this one:
1. For some reason, I couldn't angle up and down when I ready the gun, maybe it's my controller? I have no idea. Auto-aiming would be a great feature to have if manual aiming doesn't work out for a player like me. (Edit: Never mind this one, I read that you'll include it in one of your replies.)
2. After I obtained the Left Hand Key, I went fast on the selection of options, hit the option to leave the puzzle and it froze the game on me and all I could do is pause the game and exit out.
3. When I went back into a room, the game literally blacked out with no explanation.
Nonetheless, this is a great inspiration of PS1 horror games such as Resident Evil! Keep up the good work.