Starting out underground
Aground Zero drops you deep below the surface after the end of the world, with PAI, a cheery Personal AI, talking you through everything. You wake up in a protosuit that lets you mine ores and build, and PAI points you toward other survivors you can wake and bring back to your base. The goal is bigger than staying alive: expand and automate what you build, get help from familiar faces, and eventually work your way up to the surface. Along the way you will run into creatures that are definitely not native to Earth, so keep your gear and your base in shape.
Playing with friends
The game supports online co-op, and up to four players can build and mine together in the same world. There is also Remote Play Together if you want to share a session from one machine. For local co-op, only one player can use keyboard and mouse; every other player needs their own controller. If everyone has a controller, all four can use them. Splitting the work is the natural way to play: some people dig and haul ore, others lay out rooms, machines, and automation, and someone keeps an eye on the creatures that show up.
What to know before you start
This is a 3D spinoff of Aground set during the same events as that game, but you do not need to have played it to follow along. Expect a first-person sandbox built around voxel digging, crafting, base building, and management, with character customization at the start. It is a survival and colony-style game, so a chunk of your time goes into planning layouts and wiring up automation rather than constant combat. The world is open and post-apocalyptic, and the moddable tag means the experience can be extended beyond what ships with it. Controller support is there if you prefer playing from the couch.