For games of this type, funding is required at all stages of production, so one-time payments only make sense after the final version is released. Because 2 people will buy, and the rest will download from some third-party site. And the process of creating and buying graphics, music is not cheap.
Therefore, there is a high probability that the game will be available here, as a stable build. And, perhaps, it will be available elsewhere if players want to support the author with a one-time purchase. More specifics will be after the release of version 1.0.