Welcome to Your Daily Nerd Thing.  I was going to talk about Silent Hill 2 today but that game is a monster I will have to swing a giant knife at some other day.  So instead here is a video of all the secret UFO endings you can unlock in the various games.

Out of context this may seem odd.  Every Silent Hill game has several possible endings.  From the beginning they included a secret UFO ending that you generally have to do a lot of very specific actions during a playthrough to unlock.