Custom landing page
Please read this blog post on how to work with custom landing pages in general, then head over to the GitHub link below to grab your free sample code.
Just a few lines – you can find a full example on GitHub.
$riddle = json_decode($_POST['data']);
You played <strong><?php echo $riddle->riddle->title; ?></strong><br>
with the RIDDLE ID <strong><?php echo $riddle->riddle->id; ?>
<?php var_dump($riddle); /* debug complete data */ ?>