This is the content from the original Phaser cheatsheet, the site of which went down. I'm editing outdated information as I come across it.
Reference: http://docs.phaser.io/Phaser.Game.html#Game
var game = new Phaser.Game(width, height, renderer, "parent");
//All parameters are optional but you usually want to set width and height
//Remember that the game object inherits many properties and methods!