Glad to hear you loved the game!
Build 0.3 came out 9 days ago, so it's going to take a while until 0.4 is out. We make our builds very big (0.3 is like 100k words) so they take a couple months to make.
If you want you can follow the progress of the next build here: https://twitter.com/minohotel
We're just getting started with the story we want to tell, honestly, it will probably take a couple years to fully wrap up the game.
We don't do deadlines or timelines, really, other than a blueprint of sorts for the story. A lot of vns in this niche work with a monthly schedule, with builds around 10k words long, which is practical and constant but we prefer to have every build have a self contained "episode" of sorts with tension ramping up throughout the build's content, eg. Build 1 is about introducing the characters and solving a conflict with Argos at the end, build 0.2 is about getting your first guests, 0.3 is about managing the guests and completing the two projects, etc.
Since we have a set of story beats we want to hit per build, they tend to be bigger and less frequent than the monthly model (also helps a lot with coding the gameplay portions). I'm sorry if it's not a satisfactory answer, but they're done when they're done.
