You are playing a Work in Progress, not a full product. It is always used, delivered, and updated under the stipulation that things may break. It is entirely free, and you do not enter into a licensing contract. The dev also listens to feedback. You are not entitled to a functioning game at this point, both legally and morally.
Viewing post in "Voices of the Void" Pre-Alpha 0.7.0 comments
Making sure both the game and the dev have a good foundation of how to update the game is important. Layering content on broken content simply doesn't work else games like Maplestory would be the best thing ever lol. Trust me a lot of games fail directly because they try to do such and let the pileup ruin the project as a whole. Fix what is there THEN add else you will also have to fix what you added on top of the old bugs which might just create new issues anyway causing massive double dipping into issues.
You are partially correct, feature creep can definitely ruin a project. However, fact is much of VotV is placeholder content or otherwise subject to change, so expending too much effort on that is likewise a waste. Gradually expanding the scope of a project while ensuring the bugs never get TOO bad is something most developers have a problem with, and this project in particular has been very forward with QA and bugfixing.
And besides, a Roadmap is an option, not mandatory. This is neither a paid project nor a project made under employment, it is clearly someone's passion. Sharing in it is nice, but it doesn't entitle anyone to the labor of the developer. They could pull the plug tomorrow, delete the game off the internet, and no-one would or, could, punish them for it.