Ok this is amazing, and my primary complaint is that the pause button appears to never be enabled because I want to walk away and come back later. I'm guessing the next tier of grayed out buttons, such as exploring the city, are just not implemented yet?
One functionality missing: seeing in advance what the cost of a given button is. The shelters for example cost 5 wood, but I had to figure that out because there was no indication of price or that the shelter button couldn't be clicked when I had less than 5 wood. With this in place, I'd call this a complete and polished game.
I especially loved the attention to detail provided with the ever-expanding map view and the zombies and the projectiles moving between the zombies, defenses, and guards. This is really, really good!
Pictured: me trying to get to population 1,000 but then needing to give my hand a rest. This is awesome!