Subnautica is an immersive underwater adventure game set on a mysterious alien ocean planet. After crash-landing, you find yourself in a vast, open world filled with both beauty and danger. Your journey takes you from vibrant shallow coral reefs to the dark depths of deep-sea trenches, lava fields, and glowing underwater rivers. As you explore, you'll need to carefully manage your oxygen supply while navigating through kelp forests, plateaus, reefs, and intricate cave systems. The ocean is teeming with life, some of which can be helpful, but much of it poses a threat.