Figured I'd come back and post some impressions now I'm more hours in, I think I've got a much better idea of what the game "is" after 10 or so hours, and what it isn't.
The world is basically handcrafted Minecraft, so they've procedurally generated a pretty vast open space, and then let the gameplay designers loose on that to come up with quests, hidden locations and so forth. So while it looks like Minecraft, it plays much more like Zelda. Especially how you unlock new abilities that allow you to more easily explore areas which you couldn't reach before. In a way that's an odd choice, as part of the joy of Minecraft is the "you can go anywhere" approach, but it makes sense that they find ways of limiting your exploration in this one in order to aid gameplay progression.
Each world is pretty huge, you certainly wouldn't want to walk it (there are fast travel points). Occasionally you find a puzzle shrine which I absolutely love, as they come with no instructions at all and rely on you to figure out what it wants you to do. They start off stupidly simple, looks like a pond? try filling it with water etc. But later on they are devilishly difficult but once you figure them out they seem so obvious, think classic point and click puzzle type stuff.
The worlds themselves are separated into zones, different creatures, plants, and resources can be found in their respective zone, so if you need a particular resource you need to look up in your little pokedex type thing to see if you've found the creature which drops it, and where it is on the map, some items are rarer than others and require more work to hunt down and obtain.
Once you have materials, you can do a few things with them. The first of is crafting things by combining items together, unfortunately crafting requires a recipe, and these tend to just unlock at key points in the game, or when you complete missions. But I'm only like 10 hours in and have about 200 recipes for various items already, I'm sure some of the best recipes are probably hidden away in the late-game somewhere.
Secondly, you can cook some of them - cooking is a bit more freestyle and lets you discover recipes just by chucking things on fire, but this doesn't feel partially deep or challenging.
The third thing you can make are building blocks or tile items, some are just nice little decorative items, but others are needed in order to build specific things.
The building, like crafting, seems to require blueprints which you unlock primarily via story progression. But once you have a blueprint you'll then need to find all the items you need to craft the relevant blocks or items, then once you have all these, you just "Minecraft" them together and voila, you've made a little room. This part of the game is really well done and seems to offer way more depth than it appears to have at face value.
Basically you put flooring down and then some walls, and depending on the size of the space this creates an extra small, smalll, medium (etc etc..) room, then by decorating that room with certain items it'll become a specific type of room (e.g. storeroom), I think you can figure some out without the blueprints, but due to there being so many combinations I don't think you're likely to stumble upon many by sheer luck. (e.g. one requires a small room, with 3 fires, a chest, 1 stack of hay and a shovel), plus the recipes for construction the items are story locked most of the time anyway so even if you did know-how, you couldn't make the parts yet.
Now this is where things get interesting, as I almost didn't buy the game as I couldn't see the appeal of 'single-player minecraft', but your town has villagers in it (more come as you progress the story), and despite them looking like cute generic JRPG townsfolk, they don't just wander in random patterns. They have a whole day-night cycle, and depending on what you've built, find themselves jobs and help out with the upkeep of the town.
So if you make a kitchen, one might become a cook and start taking the items you put in the chests and making food (which goes on the tables), or if you turn some of the lands into farmlands, then they may pick up tools from the tool shed and help replant seeds and water them for you.
It's great, I just rock up into town like a superstar, plonk my items I've gathered into a chest. And watch them scurry around like busy ants doing all the monotonous jobs for me. I also like how they'll only do things you've already figured out for yourself, so if you discover a new food recipe, and put items in a chest, they'll be able to make that food to from then on.
Now there are some smoke and mirrors involved, like how your town only ever seems to be invaded when you are in it (or nearby), but I guess they are trying to get you, the builder, and it would be annoying as hell if you had to keep returning to it, so i'll let it off. But it does seem to always do the AI stuff even when you are away from it, so you come back after exploring and can see they've been busy.
I think that's what I enjoy the most, how the game has this constant feel of progression. You choose to explore? you find some new items or do some new shrines, you choose to stay in town and improve things? your citizens become more useful and reward you with little hearts, or obviously you can crack on with the main story missions, and progress the plot forward. It's impossible to play this game and "waste" your time, which is nice.
Downsides so far are probably that the combat is dull, I tend to just loot and let my sidekick do the dirty work now, and the game has no real difficulty, if you die you just go back to base, which can mean it's an annoying trek having to find where you were again, but nothing is ever really on the line.
So far I'm feeling like it's probably a 9/10 game, just because of the town stuff. I've ranted for ages and haven't even gone on about how complex some of the other town systems are yet, just the farming part is up with say, harvest moon, in terms of mechanics, having to make irrigation networks etc.
Loving it so far