Thanks for feedback. It was definitely hard juggling making the game legible and making it atmospheric. I'll try to explain what I was trying to get across...
Ghosts are represented by translucent flickering pixel clusters that move. When you press Z/Space, there's a flash in front of your character that represents a camera flash. The closer an enemy is, the more damage and knockback they take from your camera.
All the rooms have doors in them, which you enter with Z/Space. They are all the same color and all 2 pixels wide. They are also usually a source of light in rooms. A couple doors are locked. To unlock them, you simply need to walk over the keys (which flash to make them more visible). You just have to reach the last locked room to win.