If I were you, I would start off with a smaller low tier patreon with a smaller payment that at least allows past paywall stuff, as well as gains you far more people since it (if you do this) will be a relatively small sum. Larger sums like $15 would be better suited for something like being able to have something pertaining to the Patron(s) or be able to vote in some of the matters pertaining to the game. Its not that people are hating on you and your work, its that the price for looking at some of the content is pretty high to some that are on here - especially with a game this early in development. Its better to ask for small amounts from a much larger amount of people rather than ask a larger sum from a smaller group - cause what if some of them leave? When there's little sales of a product, you make it cheaper to bring in more people. When sales get extremely high you increase the price to level out the consumption of said product. In this case, it'd be better to start off small and work your way up.
I honestly hope this advice reaches you well, as the game honestly looks really good and I don't want to see it crash and burn.
I did edit my review with advice similar to this and some examples of really popular game communities on here with creators that have Patreons for some examples.