Hello engineers! Welcome to 0.4.0! We introduce to you the farming, iron ore and many more cool things for you to play with! It's a large update so enjoy our launch trailer, and we really hope you guys will enjoy the changes we've done!
Due to the sheer amount of world related things we've added to the world we strongly advise you start a new world. Upgrading an older save (0.3.x or older) may result in some of the farming plants missing from the world, certain door and window blocks missing, and other vague crashes and issues.
https://www.youtube.com/watch?v=gANYIP_LSPc
Full list of new features and fixes: http://forums.keenswh.com/threads/7390250