It's possible that your current savegame file would be incompatible with versions of the game from other sites. You won't know for sure until you try it (there's a backup procedure here, so that you can back up your game before you try anything "dangerous.") No updates to the game have been released yet.

To start another village, go to the Menu screen and click on "Change Tribe." You will see 5 slots that you can use to play 5 games simultaneously.