All users who buy an early adopter license get a small little badge on their avatar saying "1st" for being an early adopter.
If you purchased an early adopter license when you were logged in, it should have automatically updated your account to show the badge.
If you paid when you were logged out, or created an account after paying for the license, you may not have your badge! To get your badge, simply send an email to licensehelpmfm@scirra.com with your username and Paypal transaction ID.