phaser/examples/camera/basic follow.js

var game = new Phaser.Game(800, 600, Phaser.CANVAS, 'phaser-example', { preload: preload, create: create, update: update, render: render });

var baddie;
var keys = Phaser.Keyboard;

function preload() {

    game.load.image('background','assets/misc/starfield.jpg');
    game.load.image('ufo','assets/sprites/ufo.png');
    game.load.image('baddie','assets/sprites/space-baddie.png');

}

function create() {

    game.add.tileSprite(0, 0, 2000, 2000, 'background');

    game.world.setBounds(0, 0, 1400,1400);

    for (var i = 0; i < 10; i++)
    {
        game.add.sprite(game.world.randomX, game.world.randomY, 'ufo');
    }

    baddie = game.add.sprite(150, 320, 'baddie');

    game.camera.follow(baddie);

}

function update() {

    baddie.body.velocity.setTo(0, 0);

    if (game.input.keyboard.isDown(keys.LEFT) && !game.input.keyboard.isDown(keys.RIGHT))
    {
        baddie.body.velocity.x = -155;
    }
    else if (game.input.keyboard.isDown(keys.RIGHT) && !game.input.keyboard.isDown(keys.LEFT))
    {
        baddie.body.velocity.x = 155;
    }
    else if (game.input.keyboard.isDown(keys.UP) && !game.input.keyboard.isDown(keys.DOWN))
    {
        baddie.angle = 90;
        baddie.body.velocity.y = -155;
    }
    else if (game.input.keyboard.isDown(keys.DOWN) && !game.input.keyboard.isDown(keys.UP))
    {
        baddie.angle = 90;
        baddie.body.velocity.y = 155;
    }
}

function render() {

    game.debug.renderCameraInfo(game.camera, 32, 32);

}