Help with collide and performance!

[Tourniquet]

Hi,

as I said before I'm still very new to phaser and javascript. I read tutorials and wanted to test out some basic stuff. Unfortunately even there are some problems, but I'm not sure what I'm doing wrong.

 

Atm you can only jump and I've choosen to collide my character with the platform. Sometimes if you start the game or jump, the character does not collide with the platform but I don't know why.

 

Also i tested this on my phone and fps are very low ~11 is there any way to speed things up?

 

[>click<]

var y = 0;var j = 2; // 3 Lebenvar bird;var platforms;var cursors;var heads;var score = 0;var scoreText;var life = new Array();// Create our 'main' state that will contain the gamevar mainState = {create: function() {    // Set the physics system    game.physics.startSystem(Phaser.Physics.ARCADE);    //game.physics.startSystem(Phaser.Physics.P2JS);    background2 = game.add.tileSprite(0, 0, game.width, game.cache.getImage('background').height, 'background');    platforms = game.add.group();    platforms.enableBody = true;    var ground = platforms.create(0, game.world.height - 52, 'ground');    ground.scale.setTo(4, 2);    ground.body.immovable = true;   this.bird = game.add.sprite(800, game.world.height - 250, 'bird');    game.physics.arcade.enable(this.bird);    this.bird.body.bounce.y = 0.2;    this.bird.body.gravity.y = 800;    this.bird.body.collideWorldBounds = true;    //  Head    heads = game.add.group();    for (var j = 0; j < 3; j++)    {        life[j] = heads.create(10 + j * 50, 10, 'head');    }	j = 2;    //  The score    scoreText = game.add.text(1300, 20, '0', { fontSize: '52px', fill: '#fff' });    // Call the 'jump' function when the spacekey is hit    var spaceKey = game.input.keyboard.addKey(Phaser.Keyboard.SPACEBAR);    spaceKey.onDown.add(this.jump, this);    // Call the 'jump' function with touch    game.input.onDown.add(this.jump, this);    game.world.bringToTop(this.bird);},update: function() {		    //  Collide the bird with the platforms		    game.physics.arcade.collide(this.bird, platforms)// Debug	game.debug.text(game.time.fps || '--', 2, 100, "#00ff00");},jump: function() {    if (this.bird.body.touching.down)    		{        		this.bird.body.velocity.y = -750;			}},restartGame: function() {    this.game.state.start('menu');},};

[Tourniquet]

No one got an idea?

 

I've tried both

 

game.physics.startSystem(Phaser.Physics.ARCADE);

game.physics.startSystem(Phaser.Physics.P2JS);

 

But it's still the same, sometimes it works, sometimes it doesn't. =/

 

My main problem is that it's really slow on mobile phones.