As long as its legal in your country, then 18 should also be fine. The age of 21 just serves mainly as a catch all for countries that may have more stringent guidelines.
Is there gonna be the password to the Duffel code Is there any way to play Alpha? Adventures like If there's a link to it. Or it's just gone for good. By the way you didn't update by the way. I still see the same things and I cannot play the new version.