Based on their history of the devs with their previous games. I can be confident to say it's not a scam. Although it seems they have put this game in the back burner for a long time due to real life stuff.
That being said. There has been no update whatsoever, for months, not even a post saying "I'm sorry, we are very much behind but are still working on it". Which itself really disappoints me, I understand that they cannot sacrifice their entire time for creating a game if they have other obligations but there is no reason not to at-least inform the people who have pre-ordered this game what the status is. Just anything to let us know what's going on. I don't think it's asking much....