Survival, sandbox crafting games are very popular and very common these days. Ark, Conan Exiles, Valheim, Enshrouded, Terraria, Stardew Valley, and of course Minecraft, to name a few. All these games (and many others like them) are great.
However, I think Wurm stands above all of them for being a far richer, deeper, and more meaningful experience. Unlike those other games, you're not going to be able to build a giant castle in a couple nights, or have to complete a linear campaign of progression to "unlock" components. Everything is available to you from the start in Wurm, the entire world is open to explore and build and manipulate from the moment you login to the game. The only limiting factor will be your own knowledge of crafting recipes and your character's skill at completing those recipes in an efficient and timely manner.
Wurm has a short and basic tutorial, but outside that there is no hand-holding. There is no starter area where you get to learn the ropes, where things will be beginner friendly. Wurm is just a giant world full of possibilities for you to discover however you want. It is a slow, methodical game. It requires patience, but that is what makes it very relaxing.
Wurm has a myriad of character skills you can improve in. From cooking to mining to carpentry to fighting. You can be a jack-of-all-trades, or master in a few.
The best way to play Wurm is with some friends. This game rewards teamwork. It is meant to simulate a real functioning society. Go on a journey with your companions, find the perfect plot of land, set down your deed to create a settlement, and start building your little village. If you are on a big enough server, you may get some visitors who will come by to offer you help or even trade some resources you need. If PVP is enabled, you will need to think about defenses, crafting weapons and armor and stone walls.
Wurm's world is alive. Animals and plants grow and age on their own. Cut down a forest and it will eventually grow back again. Animals will age, grow, and eventually die. Destroy a population of wild horses in your area, no more wild horses will appear there. Speaking of forests, these are the best forests in any game ever. They truly feel like forests. They are not just wood resource hubs, but deep and dense and a bit scary. You can easily get lost in them if you are not careful. I have found myself literally walking in circles on more than one occasion. Bumping into a hostile creature on accident is a far greater possibility here.
Combat is secondary to this game, but it is still important. Monsters are not tied to a specific region. It is very possible for something horrible to stumble into your village, and you will need to find a way to deal with it. This means you can never just rest easy without keeping your head on a swivel.
A smart group of players will try to specialize their skills. Not everyone needs to be the hunter and tracker. One player can master cooking all the delicious meals (and there are literally hundreds of recipes), one player can smith the ore, one player can wear the heavy armor and defend the village. The list of specializations goes on and on. And once that happens, players will naturally begin trading and bartering like a real economy. Found the best warrior in the land? Pay him in pelts, mined gemstones, and meals to rid your town of a troublesome troll. Need a whole ton of iron for your armory, pay an expert miner to gather it for you and pay him in a nice suit of armor. Silver coins can also be found and used as a currency as well. There are endless possibilities for cooperation.
The crafting system is the heart of this game. Every object you create feels plausible and monumental. Creating a basic wagon, for example, will require you to of course gather wood and ore, craft planks, shafts, and nails. From there you will craft each wheel at a time, nailing the spokes together with your wood, then fitting them together, and finally crafting the wagon bed and then putting it all together. Any other game of this genre would greatly simplify this process, but Wurm makes you earn every step of it. Because of that, you will feel a great sense of satisfaction in every creation you own. No other game of this type will make you feel this like Wurm does.
I keep coming back to play Wurm because it did what no other game like it has done since. I wish someone could learn from Wurm and do it with modern graphics and other modern conveniences, but nobody has yet. Even so, the lack of these modern features takes nothing away from Wurm. Once you grasp what this game is trying to do, it won't let go of you. You will never be asking yourself, "I have nothing left to do". You will always have more you to do, more that you will want to do. There will always be a new thing to craft, a new place to explore, and a new goal you will set for yourself.
Wurm may not be for everyone, but if you are looking for a survival crafting game with more depth, something you can really sink your teeth into, Wurm is the game for you.
