The next beta update (coming next week) will add secret tunnels that connect the world and a host of other improvements to the overworld and dungeon generators.
http://steamcommunity.com/sharedfiles/filedetails/?id=860018023
Because these improvements affect the overworld and dungeons, you may want to back up your copy of Songbringer if you are in the middle of playing a certain world. Just copy the entire Songbringer folder somewhere and then run it from that folder instead of Steam.
If you don't make a backup copy what will happen is just that the layout of the overworld and the dungeons will have changed. Your save file will still have all the items you have obtained. You might need to re-explore the map a little.
Cheers,
Nathanael