Thanks for you feedback! I see how the versioning and current state of the game could be misunderstood by the broader game audience. I just don't like the word Demo just because it implies that I don't want to give my game away for free and that until you pay, this is all you get. But if I can't think of a better word to call it so people know it's incomplete, then I'm not opposed to adding Demo to the title.
A 'Demo' is an incomplete game, but if you want to use 'Trial' or 'Prologue' instead then you are welcome to do so. The issue with 'Prologue' is that it is implied to be prior to the events of the 'main' game and thus it may confuse some users. Trial is another alternative to Demo if you want to go that route.