Natural Selection 2 developer Unknown Worlds has released its latest game, Subnautica.

The underwater, open-world adventure game Subnautica has been released for PC on Steam and the Arc platform.

Subnautica was announced in December 2013, and shown for the first time in April 2014 at PAX East.

In the game, players will explore an alien ocean with mysterious creatures that dwell within the depths. While trying to avoid creatures planning to make a meal out of them, player will craft equipment, interact with ore docile wildlife and pilot watercraft. Using the latter allows them to explore coral reefs, volcanoes and caves.

A list of key gameplay features is provided below.

Dive into a Vast Underwater World

After crash landing on an uncharted world, players navigate a wide array of ocean biomes in search of answers. From sun-drenched coral reefs to deep-sea trenches, the surroundings and life forms change as explorers delve deeper – posing new threats.

Scavenge, Craft and Survive

• The adventure begins in an emergency Life Pod, where players must immediately find water, food and resources, then venture forth to discover blueprints and materials for more advanced equipment to increase their chances of survival.

Construct Underwater Habitats

• Survivors choose from a number of modules and components to build a custom underwater base, adding furnishings, vehicle bays, observatory chambers and more. As players dive deeper, pressure increases, so they must manage the strength of their base hull to stay safe.

Unravel the Mystery

• Never-before-seen architecture, a mysterious disease affecting sea life and secrets await in the deep. Players will discover the truth behind their crash landing and seek the means to escape the planet alive.

Play Your Way

• Subnautica allows players to explore the ocean and manage health, hunger and hydration in Survival mode; endure the pressure of only ONE life and no O2 alerts in Hardcore mode or, unleash their inner visionary in Creative mode – which allows them freedom to explore the ocean and build bases with no health upkeep or resource costs.

Over 1.5 million folks have played Subnautica since the first prototype was released  in 2014. The game is now officially out of Early Access and will run you $24.99. Currently on Steam, it's on sale for $22.49.

Subnautica is also available on Xbox One through Xbox Preview. A recent update on Xbox One added the latest content available through the Steam version.

A full release for Xbox One hasn't been set, as it's still in development.