ADD TO Preloader.js :::

--preload
this.load.atlasXML('spacerock', 'images/spritesheets/SpaceRock.png', 'images/spritesheets/SpaceRock.xml');
	



ADD TO Game.js

this.totalSpacerocks;
this.spacerockgroup;

-- create
this.totalSpacerocks = 13;

-- buildWorld
this.buildSpaceRocks();

-- ADD
buildSpaceRocks: function() {
    this.spacerockgroup = this.add.group();
    for(var i=0; i<this.totalSpacerocks; i++) {
        var r = this.spacerockgroup.create(this.rnd.integerInRange(0, this.world.width), this.rnd.realInRange(-1500, 0), 'spacerock', 'SpaceRock0000');
        var scale = this.rnd.realInRange(0.3, 1.0);
        r.scale.x = scale;
        r.scale.y = scale;
        this.physics.enable(r, Phaser.Physics.ARCADE);
        r.enableBody = true;
        r.body.velocity.y = this.rnd.integerInRange(200, 400);
        r.animations.add('Fall');
        r.animations.play('Fall', 24, true);
    }

},