These releases are meant for people who want to support me in getting to a final build of this game (with all the content meant for Gaia, the planet you crash on), obviously the final build which will be released on Steam next year won't have any payments per update. This is an alternative of supporting akin to Patreon, because it's pretty costly nowadays to spend time you can spend on something else developing games...
This is some sort of early access as well and an opportunity to shape the game by yourself by offering feedback, suggestions, etc. before the final build on the alien planet, after which a new stage of the game would be necessary (a sequel).