I have the following: game.createScene('Main', { backgroundColor: 0x630909,init: function(message) {var player = new game.Alien(100,100);}, keyup: function(key) { if (key === 'SPACE') { var tween = new game.Tween("call my player object here"); tween.to({x:800}, 1000); tween.start(); } }});How can i call the "player" object in my tween