Character creation is very basic. The color palette allows pretty much any color you like for any feature, so if you want to be a blue kid with green hair (or another, more mundane, color scheme) then the sky's the limit, though many of the colors are a bit too saturated, imo. There are placeholder spaces for other options but only gender, eyes, skin, and hair can be tweaked at the moment. Character animations are also kind of rough, and the (voiced) quests also have some audio missing (it being an Alpha, and all).
The game has a story mode (with familiar-style quests and an overarching plot), and a pure sandbox free-build mode. Story-mode world maps are static, but eventually the plan is for multiplayer worlds to be procedurally-generated. I started with the story mode, and got a simply-animated cutscene depicting the ill-fated landing attempt of a colony ship onto the planet 'Maria'. My first quest after awakening at a shuttle crashsite was to gather some wood to make a shovel so I could dig supplies out from under the shuttle debris to help a fellow survivor. Lore-wise it seems characters have 'replicators' that just need some raw material to synthesize whatever tool they need made. For example, to make medicine you just need some cuttings from the right plants and the recipe learned, and the replicator does the rest.
Despite a tutorial pop-up which explained how to learn and use crafting recipes, it still took me a few moments to figure out that attacking trees (left click) does not work like it does Minecraft and I had to right click on them with my equipped tool in order to actually chop them down. It is also a bit fidgety to know what to target since interactive things don't light up and aren't marked in any way, so you need to make sure you're lined up properly and do some test clicks to see if something is harvestable. With trees, holding the mouse button = faster chopping, though some types of trees need more chops to cut down than others. I watched a weird alien critter wander by and wondered what would happen if I poked it with my knife, but decided to finish getting the medical supplies before getting too adventurous.
Upon replicating a shovel I immediately tried to see how deep of a hole I could actually dig in this voxel world. I got a decent ways down before my shovel finally broke and I realized it's probably not wise to dig straight down leaving sheer walls and no way to get out. So I'm not sure how far down it's possible to go (or if there are underground features like caves), but it seems possible to dig out and entire underground complex if you wanted to spend the time (and having a better quality shovel might make it go quicker, unless quality only affects durability -- I'll have to test that theory). There is also no lighting change underground, which makes it trickier to discern the depth of a hole (or even where it is) if you're above ground looking for it. Small spaces also force you into first person perspective which can make orientation a bit difficult as well. I decided to come back later with better tools to make more progress with my digging experiment.
I noticed that the deeper you dig, the more you start getting units of graphite, sulfur, and other material besides just dirt. Unlike Minecraft it appears to be a % chance based on where you are digging rather than set nodes that you can see (though you can use a 'Handheld PC' to scan for various deposits near you).
Once I got back on track with my quest, I received more recipes for my replicator including one for a sword, so I crafted one and went looking for one of the critters I'd seen earlier to see how combat worked (basically click stuff til they die similar to Minecraft). They turned out to be cowards that didn't even fight back, and once I killed one I received some more food-based materials (meat and animal fat). I also found a new type of critter; a furry thing that was actually hostile on sight but who died just as easily.
The newbie quest eventually sent me north to look for more survivors, so I headed off, gathering samples of any new flora I found along the way. I'm not sure how plants regenerate in this game (or if they do at all), so clearcutting might not be the best idea. Once I found the second survivor camp, more quests opened up after talking to the folks hanging around. I also bought a headlamp so I can keep my hands free for tools in the dark, which seemed like a good investment -- you can use a Bed to speed up nighttime and regenerate your Stamina, but it's not instant and is a little boring to wait through just to avoid the dark. I also traded some of the Meat I had for a bow and arrows and some new armor. Now that I had some freedom to wander off the quest chain and into the wider world, I started looking into some of the other windows in the game, like the map (which shows coordinates and custom markings and allows fast-travel to key locations for a small fee so getting lost shouldn't be an issue).
From looking at the types of parts available to buy from the NPC vendor, vehicles and things like stationary defense turrets are also craftable, and you can apparently customize the appearance of weapons and other objects via the 'Creation System' window which at the moment confuses me more than anything else but has a lot of options to mess around with. From a cursory glance it looks like a more complex version of Spore's building/vehicle creation system where you can drag shapes into various configurations as well as choose paint/textures or even add custom decals onto objects. There is also an option to import other people's creations into your game as well. I was never good at anything other than Creature creation in Spore, however, so this sort of feature would be of limited appeal to myself, though I know some people would probably love it and could probably make some cool stuff with this editor (below is a pic of a player-created vehicle that I imported into my own game).