Hey Lightifer! Thanks so much for asking and expressing your interest. So, we've been in development of another project, working title 'Virtue', for roughly a bit over a year now. However, due to a number of things (e.g., all of our devs have other jobs too) and how ambitious the project is, we are unable to provide a tentative release date on that one.
That said, the best way to keep up with us is likely to "follow" GoblinWare on Itch.Io, and/or follow @GoblinWare on Twitter. More, if you want to send your direct contact details to firstname.lastname@example.org and email@example.com, we will be sure to shoot you an e-mail or let you know directly (with as much heads up as we can) about anything new we're putting out.
Due to the popularity of SOPHIE, we've been flirting with the idea of extending it, adding new levels, more narrative, etc. We're certainly about to release a version 1.04 which polishes a number of previous things that all the feedback has brought up (but which is not content-related so would not be considered a 'major update').
Hope any of that helps!