I'm trying to be a bit more regular with my news updates. So I've just finished the main parts of adding walls back into the game. It was a major pain, I had to completely overhaul the way the AI perceives walls.
The old method was using a flood-fill of the navigation mesh to determine which areas were enclosed by walls, and which gate was required to access which area. This method fell down though when walls crossed map zone areas and got partially unloaded.
Anyway, I used my mighty brain power to squeeze out a new method, and it works pretty nicely now, much better at handling awkward situations with less bugs. It even accounts for walls within walls, and multiple gates in a wall, and other crafty things. The only problem it faces is that it will all spaz out if the players builds gates inside-out facing.
In the meantime Sam has added water to the game, though you won't see it in an update just yet. I'm holding it back for the new biomes at a later date.
Also, due to a minor mis-communication I accidentally put the game in the Steam sales for 33% off. I'm thinking of actually increasing the price a bit more soon, so now is actually the cheapest you will ever get the game for if you don't already have it.