I understand that this game is in development, but given that some of the art is Public Domain and others are licensed art you haven't used yet, shouldn't there be a credits page where you can give credit to those artists?
Potentially not errata, but an issue to clarify: in your introduction to the game, which is titled Songs of the Northlanders, you refer numerous times to RedHack in text (ex. under "What is Songs of the Northlanders?" your para begins with "This game is..." and then the second to last sentence says "RedHack is a game...") as though RedHack is the title of the game.