As I replied to your previous comment too, so I will copy-paste it:
So then it was 5 dollars the same way we are doing it on Patreon and it is written on the post itself here:
Please be aware of the following!
- This purchase will not be updated monthly
- This is not early access for the final retail product
- New monthly releases will appear on our itchio profile as they become available
So the new one that is 19.99, buys you the whole game from now to all future updates :)