In the spirit of Halloween, lets talk about the most scariest/messed up/bizarre game you ever heard/played. Mine would have to be a little, small indie game called Yume Nikki. You play as a "hikkikomori" (or shut-in). You traverse her dreams looking for 25 effects. These effects do different things to the main character. These can vary from giving her cat ears and tail that attract NPCs to even turning her head into a hand with an eye in the middle of the palm. Then there's the full-screen events.
Link related, it's one of the full-screen events: http://www.youtube.com/watch?v=by3hojNV5Nc