Two demos were made for the game (download): one of them has a single mission not in the main game, while the other has three unique missions that show the events leading up to the beginning of the main game. The one-mission version reports itself as 'version D1.01', while the three-mission version identifies as 'version D2.00'.
Last patch release is V1.09. The GOG.com release is already patched.
Terra Nova World Editor allows creating your own land scepes for the game. heightmaps are also available.