game.js

function update() {
    if (game.input.keyboard.isDown(Phaser.Keyboard.LEFT)) {
        player.animations.play('left');
        player.x -= 3;
        var pos = JSON.stringify({
            x: player.x
        });
        sock.send(pos);
    } else if (game.input.keyboard.isDown(Phaser.Keyboard.RIGHT)) {
        player.animations.play('right');
        player.x += 3;
        var pos = JSON.stringify({
            x: player.x
        });
        sock.send(pos);
    } else if (game.input.keyboard.isDown(Phaser.Keyboard.UP)) {
        player.animations.play('up');
        player.y -= 3;
        var pos = JSON.stringify({
            y: player.y
        });
        sock.send(pos);

    } else if (game.input.keyboard.isDown(Phaser.Keyboard.DOWN)) {
        player.animations.play('down');
        player.y += 3;
        var pos = JSON.stringify({
            y: player.y
        });
        sock.send(pos);
    }
}