It's really fun and addictive, but if you want to win by creating a constitution the game's incredibly easy.
You just reclaim the city hall and a few buildings around it, then you begin drafting the constitution. Whenever a horde of zombies attacks, ignore it and just keep ending the day. In the end, you only have a few buildings, but you still win.
But I love this game. I've played it a lot over the past few months.