Your mouse has a small area of visibility around it at all times. Left clicking uses your flashlight. Right clicking uses your knife.
Ghosts can be stunned with the flashlight, which leaves them vulnerable to the knife. When hit with the knife in this state, they die. If hit with the knife while not stunned, they dodge.
Ghosts left alone long enough will start to laugh. If left laughing, they will kill you. This can be interrupted with the flashlight or knife.
The sleeper is a special ghost that looks like the other ghosts, except with closed eyes. When hit with the knife or stunned with the flashlight, it begins to bend itself out of shape. It must be sliced with the knife to prevent its transformation, once per stage of transformation. If it fully transforms, you die. If you slice it when its in its least bent shape, it dies.
I'm not the best at visual tutorials and the resolution was too small for me to consider words, so I knew there might be some issues with this. I probably should have split it into more pages...