You're basically on some mining space vessel that enters the orbit of a large ocean planet that has virtually no landmass. The planet has and sustains life, and there have been other vessels in it's orbit in the past. Something goes wrong, and your vessel goes down, you enter a lifepod and escape. When you land on the ocean surface, you are in your lifepod, upon exiting, can see the spaceship in the distance. You have a short amount of time before an explosion occurs on the spaceship, flushing radiation into surrounding waters. Most games, the lifepod will be out of range of the radiation and you will have no worries, but swimming in the direction of the ship can kill you. You have to survive, catch and eat small fish and drink filtered water. You start with very little for tools, but the nearby environment is always "safe shallows" where you are relatively safe for the most part from hostile sea creatures and can find nearby resources to begin crafting tools inside your lifepod's fabricator. You find blueprints for new equipment, gear, and submersibles as you go along, and within a short time obtain what is needed to make the beginnings of a sea base. This is useful for too many reasons to count, but as you progress, you have to go further out into different kinds of biomes to find different kinds of blueprints for gear and building modules, etc. but also for different resources you can't simply find in the safe shallows. Within a short time you can make a radiation suit to swim in radiated waters, allowing you to make your way to the vessel, and even stop the radiation at some point, allowing you to use a different type of suit with other benefits. There are tons of biomes, resources, places to explore, sea creatures to fear, and items to find and craft. Not too mention building a sweet sea base.
Early on you can basically get the atv of the ocean, which you can further upgrade later on for a faster version, and also a say, automobile of the ocean before long, and eventually the RV of the ocean, a submarine called the cyclops. There is a lot to explore and do, with depths going from 0 surface to -1000, much of it very impossible without the creation of vehicles.
I can't say much in lacking support for this game, it's pretty darn cool, take a look for yourself.
