Okay, this game is still an Early Access title. The last item on their roadmap is multiplayer, so don't expect to be playing with other people anytime soon. I mention it now, because it is on the weekly sale for Steam right now.
What currently works: The general world creation, going around, doing stuff, and NPCs slowly building towns. Creatures fleeing or fighting. Most items are functional, a few are bugged. Some of those items will lock your current game world (not a big deal, because of what doesn't work right at the moment.) Blacksmithing and woodworking. Most of the crafting stuff that is related to that. NPCs will offer you recognition when first arriving if you lead a town. Most of farming and gardening. Shops have starting gold and items, trading for what they have eventually can leave the shop empty of gold and items you want, meaning you will have to make a new shop currently.
What doesn't work yet: The game does not yet have stone implemented. Metal is only found in cave yet, which will be changing. Onions are not working on farm gardens. Roads and jobs, NPCs moving towns when unhappy, kicking NPCs out of towns when they have low reputation, politics, armies, and kingdoms. NPC bandits are not implemented. Some blows do no damage, at other times they continue to do damage until whatever was hit is dead. Water makes animals glitch. Multiple copies of plants start building up, eventually causing the game to lag regardless of how awesome your build is (I have chopped down 7 trees which all grew in the same exact spot within each other) after a few hours (on their priority to fix list.) Optimization is not done by any means.
So what is this game? Kingdoms is essentially a simulator for building villages, towns, cities, and kingdoms in a medieval setup. Think of it as a cross between a survival game and an advanced AI simulation where you can do and be anything given enough effort and time. The concept is kinda cool, mainly because the AI is doing things different, in concept, than what is done in other games.
I figured I could make a quick video showing some of the current content, here's how you start a village: http://plays.tv/s/KpcEnmjI8MG9 Do note that you require specific perks to start a village, and that currently if you do not make one by dawn of day 2 nobody will populate it (you can still build one for yourself.) The farthest I have gone before plant lag killed my efforts was level 9 with a decent little village including a bakery, blacksmith, quarry, farm, several shops, and a bunch of houses.
Hopefully this helps people make decisions if they wish to look at this game, or if they were interested already and wanted to know more!