ig.module( 'game.entities.paddle-enemy' ) .requires( 'game.entities.ball', 'game.entities.paddle' ) .defines(function(){ EntityPaddleEnemy = EntityPaddle.extend({ update: function(){ var ball = ig.game.getEntitiesByType( EntityBall )[0]; if( ball.pos.y + ball.size.y / 2 > this.pos.y + this.size.y / 2 ) { this.vel.y = 100; } else { this.vel.y = -100; } this.parent(); } }); });