You must use valid email (avoid using email address with lot of dots or fake email, your account will auto banned) and only gmail is allowed.
This site does not permit:
Signups from Proxies or VPNs, this includes Tor.
Temporary email addresses.
Multiple accounts.
Registrations from some ISPs may be blocked due to a high incident of spam.
If you have an existing account, do not create a new one. Account usernames and email address can be changed from account settings page.
Account activation will send to your gmail to complete registration process.
accounts that do not confirm their email will be automatically deleted.
Members who have less 10 trophy points will be automatically deleted (not effected for premium/premium plus membership), so if you have not any plan to upgrade your account, don't register, you can access free build without register.