Grand Theft Auto IV/Secrets

There are a large amount of secrets hidden in Grand Theft Auto IV. Some are simple passwords, and some are Eater Eggs, and a list of them can be found below.

Passwords
To use theses, pull up your cell phone in the game and dial the number.

Heart of the the statue of happiness
If you are legal to go to Happyness Island (steal a helicopter and fly there). Go to the feet of the statue of happiness and jump off; if you land on the top platform, then run to the doors and you will run. Climb the ladder and you will see a beating heart with chains on it. This is the heart of the statue of happiness.