"Subnautica" is an underwater survival adventure game developed and published by Unknown Worlds Entertainment. Released in early access in 2014 and fully launched in 2018, the game has gained widespread acclaim for its immersive gameplay and stunning underwater environment.

The player assumes the role of the lone survivor of the Aurora, a spaceship that crash-landed on an ocean planet called 4546B. The game is set in an open-world, underwater environment filled with diverse biomes and marine life. The primary objective is to explore the depths, gather resources, and survive in the face of various challenges.

Key elements of the game include crafting tools, building bases, and managing resources to progress and unlock new technologies. Players must navigate dangerous underwater caves, avoid hostile creatures, and uncover the mysteries of the planet. The storyline unfolds through the player's interactions with the environment and the discovery of data logs scattered across the ocean floor.

As players delve deeper into the ocean, they encounter more advanced technology, alien structures, and uncover the secrets of an ancient alien race known as the Precursors. The game successfully blends exploration, survival, and narrative elements, providing a captivating and atmospheric experience for players.