Try signing-into your account first, then refresh the page, should be a banner at the top of the page stating "You own this Masterpiece" & a "Download" button there to hit for your copy. ~KC
Viewing post in The Zombie Asspocalypse - Chapter Zero comments
Go to https://itch.io/support after signing-into your account & select the button to "Email support@itch.io". After that, supply them with the email address you used to purchase the game. They should be able to help you from there if it's a currently valid email address. Good luck. ~KC