Believe me when I say it's better to not have paywalls. It's okay to do what most do and have 1 version for patrons and 1 version for public or 1 version ahead for your patrons/subscribers, but paywalls are never eagerly received, especially not for a first version.
If you want to know more, you can search for Elzee on here and what happened when he tried that. To date I know of NO developer who has come away with paywalls in a positive manner, it just makes people not want to pledge and more motivated to break the DRM and paywalls. Elzee...FallenEros.... doesn't matter, it's happened before. Ultimately as well it's taking time away from you making the game when you try to fight it.
A demo and full version fine, 1 version ahead for patrons which tends to be the norm can be fine too. Extra's for patrons is fine as well I've found.
I get that you want to be paid, but the demo or first version is supposed to be the showcase, the 'here is everything' so far so that people are drawn in. Imagine if you found a stall covered by a curtain and it the person said he needs money to show you what's behind the curtain, but you'd enjoy it. How likely are you to make that purchase without even knowing what it is or being able to see it? And if your competition or peers aren't even covering their stalls with a curtain, how are you going to attract footfall? I.e. people wanting to buy/pledge money?
Now take that example and imagine it was a curtained Burger Stall next to Mcdonalds i.e other games without a curtain (paywall), guess where people are gonna go?