Wow, thank you so much for the incredibly supportive and detailed comment! Reading things like this makes all the hard work feel worth it. We're thrilled you're enjoying the new art, story, and music!
To answer your question about the updates - because each season is so massive for this genre (we're talking 12+ hours of gameplay), we treat each one as a major new installment, almost like a sequel. For that reason, each new season will be sold separately. It's the only way we can sustain development on a project of this scale. We really hope you understand.
As for merch - we love that idea! It's definitely something we've considered. Since you're interested, do you have any favorite sites or services for fan merchandise that you've used before? We'd be curious to know what fans actually like using!
Thanks again for everything!