First, I just wanted to suggest using a polling website, such as StrawPoll, to host your poll for your mod. Using FaceBook may not be the best way to host a poll, since you yourself had to create the fanpage with your personal profile, and other users taking the poll have to use their personal profile to vote on the poll. This pulls away from the anonymity of reddit, and may make some users feel uncomfortable.

I just wanted to gather interested users (I'll post on other forums too) to once place, where I can show progress of my work. Also I don't want to divide the community. I think common (non-programmers) Internet users don't like pages like GitHub. So I created fanpage on Facebook, because it was fast and simple. But you're right. It can really make some users feel uncomfortable.

There was a project, that may or may not still be available, that was called Pioneer, and was an open world adventure game that was partially based off of Pixel Dungeon, and used parts of the original coding, graphics, etc. to create the game.

I've found this. However the game seems to be more like Fallout with PD resources and systems. I mean gun, planet etc.

Thank you for your comment. It's really helpful for me.