What hawkeye hawk said about the door opening too fast game me idea. Another awesome scare factor would be if you made the door open slowly, but when it closed behind you, it made a big booming and echoey sound and shut extremely fast. This would give the player the idea that something made it shut.
Really good map by the way. You should tone down a bit on the amount of blue you use. It would be a good idea to use different colors of lighting in places you want the player to go. I’m not sure I would know where to go if I wasn’t the mapper.