Well, you are pretty much asking people to give you money, without having anything, other than your word that they will get a product delivered eventually. Many new creators struggle to get their patreon off the ground, even when they sometimes are several patches into the game and the feedback is positive.
This is because people are cautious. People want to know that you are actually going to do something nice with their money and that you are dedicated to seeing it through, and not just bolt with their money after 2 weeks.
So, if people who have actual things to show to the public are having a hard time, how do you expect your patreon to do well with NO content to show off. I would certainly never support anything, unless I saw kind of preview of what I am paying for. As an example, some kinds of artstyle really turns me off, or certain kinds of character designs.
What if i support you and your game ends up looking in a way I really dont agree with? I could complain, sure, but what good would that do? You would probably not change the style anyway, and even if you did, you would get complaints from others who like the style and wants it to stay, AND you would waste a lot of time re-doing the art. Both of us would be unhappy, but I would be most unhappy, seeing as how I also lost money.
This is why you shouldn't expect people to just throw their money at you, without showing them SOMETHING first.