Unknown Worlds Entertainment has released Subnautica: Below Zero for Windows PC and Mac.

The new standalone expansion in the Subnautica franchise is set a year later, on the remote world of Planet 4546B. The game is now available via Steam Early Access, and you can watch the first trailer above.

You are on a expedition to the arctic circle when disaster strikes the research station in orbit above the planet, leaving you stranded and forced to fend for yourself. Like the original game, Below Zero will involve lots of resource management, crafting, base building, exploring an underwater world full of alien life, and trying to escape massive sea creatures.

Here’s a rundown of the game:

Below Zero is an underwater adventure game set on an alien ocean world. It is a new chapter in the Subnautica universe, and is currently in development by Unknown Worlds.

Key Features:

• Watch out! – Below Zero is not finished! It is in active development: Full of bugs, missing features, and performance issues. If you would like to play Below Zero when it is finished, follow our development progress. We’ll keep you informed as updates improve the game.
• Return to planet 4546B – Dive into a freezing underwater adventure. Below Zero is set in an arctic region of planet 4546B. As a scientist posted to a research station on the planet’s surface, you are tasked with studying alien artifacts… The Vesper space station orbits high above you, sending supplies, instructions, and receiving samples you launch from the surface. When disaster strikes the research station, you must improvise to survive: Construct habitats, scavenge for resources, hunt for food, and craft equipment.
• Explore new biomes – Swim beneath the blue-lit, arching growth of Twisty Bridges. Navigate treacherous ice floes on the ocean surface. Clamber up snow covered peaks, and venture into icy caves. Maneuver between steaming Thermal Vents. Below Zero presents entirely new environments for you to survive, study, and explore. Discover new lifeforms in the icy depths of 4546B. Swim through the giant Titan Holefish, escape from the aggressive Brute Shark, and visit the adorable Pengwings. Some residents of the frozen ocean will help you, and some might try to harm you.
• An ocean of intrigue – Who were the aliens who came here before? Why were they on this planet? Can you trust your commanders? Below Zero extends the story of the Subnautica universe, diving deep into the mystery introduced in the original game. Open up new story elements with every Early Access update.