At the 'Title' screen wait until the tv is centered on your screen and then press 'Start'. You will then hear a voice yell the title of the videogame displayed on the tv. This is in-joke reference to all the people who mocked Book of Memories by screaming 'Next they'll make a Silent Hill Kart Racer' etc etc.
At the 'Main' menu enter the Konami code (Up(2), Down(2), Left, Right, Left, Right, Square, Triangle, Start) to get a free Robbie Doll weapon and enable the sale of Robbie Dolls at the shop. If you have entered the code correctly you will hear a child's laugh as confirmation. This code can be enabled each time your character is loaded to get more free Robbie Dolls.