Just like with SB Nation and The Verge(these Vox Media sites share accounts), you cannot delete your account.
Anonymise your personal data and complain here: http://www.theverge.com/contact-the-verge
URLS:
http://www.polygon.com/
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.