For the TL;DR version, it's Factorio without the main character or attacking armies, but in full 3d so you can have one conveyor go over the other without the workaround of having some underground tunnels (although you do still get a pipe/mine layer underground). You can even stack buildings on top of buildings, although it looks silly.
There's some very, VERY light town management elements, but it's severely underwhelming if you're looking for a city-building sim. This is a logistics automation game, not a city-builder. You can do some decorating if you want, but I hope you're into "sprawling conveyor belt spaghetti chic". Instead, there are houses that level up if you feed them. House level raises your worker cap, so it's kind of important, but if you're playing the game by making conveyor chains for everything, less so. Experience only goes up, but there is a "happiness" meter that fills up only temporarily as you supply needs like food, water, clothing, medicine, etc., with higher-order needs unlocking as house level progresses. Sadly, happiness doesn't really do much besides being a milestone you only need to achieve for a moment and hit the button to get the reward before it drops, to get a reward of... a higher house limit. There's an issue of your reward for sending workers to do jobs that fulfill needs like food is to get more workers you can send on more jobs to feed them, but none of that actually helps you achieve the goal.
Workers can do anything in the game, even have complicated scripts of harvesting and delivering from multiple locations if you want, but because there's a worker cap in the game and workers are pretty slow, it's better to only use workers for harvesting and dropping raw materials onto a refiner or a chute that leads to a refiner. There is no day/night cycle, and workers never go home, so feel free to put all your houses on one island and then spawn workers on the far side of the moon with no path back, they'll work forever. Likewise, the game runs on that survival game physics-defying crafting logic where you can somehow mush a couple metal bars and a coconut together by hand at a "work bench" and get a working nuclear reactor. There is no power supply needed for the conveyor belts, and a sawmill built out of a few logs and some rocks can cut 2 logs per second into planks, but they have workers pulling infinite shifts to "power" it.
Also, you can delete most buildings and get your resources for building them back (items on conveyors you mess with teleport to your town hall). You can even delete workers(!) and re"build" a new worker elsewhere(!), meaning that if you are doing this game in phases, it's entirely possible to deconstruct nearly everything and start your whole production line over from scratch, with only house levels not coming back immediately. Especially if you're trying to skimp on workers, just plain deleting the whole production chain for one product once you have enough of that thing is mercenary but an easy way to bypass a lot of the logistical snarls you might otherwise have late-game. Ultimately, the game is a big list of "make 50 of this thing so you can unlock the next thing so you can make 50 of them to unlock the next thing so you can unlock the thing you need to win the scenario." You might think it's a great idea to cram everything in tight early on to minimize supply lines, but a key strategy is remembering to leave yourself enough room to build all the other things you're going to build later on, as you start making products that require 4-5 raw materials, which will never [i]all[/i] be on the same side of the map, and will require around 20 building churning out all the intermediary products just for one product line. (Protip: as soon as you start a scenario, delete all the houses before they have any experience to lose, and rebuild the town with the houses in a single cluster away from any raw materials so houses don't fight for space with the factories. This also helps make sure you don't have difficulty having one school or store's access range reaches all your houses.) Inversely, many maps are designed with resources in the way of others, like trees blocking off access to a wheat field, and trying to destroy one to get to the other creates shortage problems, while trying to exploit both leads to cramped areas that require multi-level conveyor tricks to make supplies go over other buildings...
There are 8 "scenario" levels with a pop-up box tutorial on the first level to guide you step-by-step through half a level, and they you're just tossed into the deep end to figure out the rest yourself. I'm fine as someone familiar with this kind of game, but someone less used to the genre may struggle. There is a "help" menu, which is woefully misnamed, because at best, you can reverse engineer the supply chain if you stick at it. (The system desperately needs to let you click to go to what the target object's help page says, and formulas that [i]consume[/i] the object to be listed so you can use the help menu to go [i]UP[/i] the supply chain, not just down.) Worse, the help menu simply has nothing to say about most objects besides what a building might produce or the sale value of an item. Minecarts, for example, have no introduction or description in the game AT ALL. I had to build one, only to find it didn't work. Apparently, after busting my butt to make the stupid things, it turns out they're slower than workers, they can only carry [i]specific raw materials only with no warning in the game they are limited and with no other mechanics acting like this[/i], and the hurdle of programming them is greater than just using more conveyor belts like I was already doing for everything else. It turns out that they're really meant for being driven by trains to make them go fast, but the game doesn't tell you that, it doesn't tell you anything but that you unlocked minecarts and minecart tracks [i]two whole scenarios[/i]/about 10 game hours before the steam engines that make them in any way useful.
Then again, as mentioned, there's no combat. There's no time restraint. The workers don't even care if you don't feed them too much. (If you do, it involves assigning a worker to go pick food, deliver it to their own house, and then pay you a coin for telling them to forage food themselves. They have infinite coins to give, and without a REAL trade system to export things off the map (rather than a factory), the worker houses are kind of the sink to the economy to drain all the random consumer junk you produce.) It has bright, if simple graphics, and no real story. It can be relaxing... if you're not realizing that somewhere near ground floor there's a snarl in your conveyor traffic, and now you have to delete three floors of other conveyors just to get line of sight to the problem. If it weren't for how complex the logistics of the game can get, this would be a perfectly fine game for kids. Then again, I played games as a kid based on simplified wiring robots together, so maybe a certain subset of kids will love this sort of thing?
That said, the lack of any real pressure can make replayability an issue. You just gain more stuff forever, and there's no reason to advance from the start again when much of how you're going to build is based off the map's win conditions and where the natural resources are located, so there isn't much sense that there's a reason to do anything differently.
Of course, there [b]IS[/b] a Steam Workshop filled with level editor maps, so you can get more playtime that way.
It's fairly cheap, it goes on sale, and it's definitely a niche type of game for those who like building [i]EFFICIENTLY[/i] whenever you have base-building in a game, so if you're that sort of person, this is just different enough from most of the other games in the genre that even if you don't stick with it long, you'll be satisfied enough you won't regret the purchase.
