Are you open to changing the design at all?
The sooner you can get feedback and shape the direction of the project, the easier it's going to be on you in the future. I like that you want to keep this game to yourself, that's honestly better for me. I think it should be yours, but I worry you are setting up for a game that needs a full team so that you have to be a full team.
You aren't doing a bad job on the coding or writing or anything, but the art is the star here. I want to chat with you about focusing this game to make the art the backbone and only using the gameplay and story to enhance that for players.
We can chat more on discord if you want. No pressure. RootNeg1Reality