Becoming part of the $12 membership allows you to redeem a code for the game on Itch, which you can then access forever. If there’s any confusion I am here to answer any questions you may have! ^^
I just want to say that I so appreciate a developer that actually allows their customers to pay once and maintain access to their game and future updates. It feels weird having to say this, but as it seems like so many developers on itch and other platforms require their customers to maintain a current membership to play and or dl updates now a days. So anyway, thank you for having a completely reasonable purchasing process and not requiring a monthly membership to be maintained to play your game.
To anyone who may be confused, when you purchase the $12 membership the code you get adds the game to your "Owned games" on itch, you will permanently have access to the current dl links through itch even if you cancel your subscription on Patreon.