Hey, it used to be that way (every update was separate and would eventually become free) so Itch.io could match our Patreon / SS model. But that was causing confusion since Itch is more of a store, so since our release on Steam we moved to an Early Access model, where you pay once and get future updates for free. From now on it's one project and future updates will be uploaded on this page. Hope you enjoy it and you will not run into this issue on here in the future!