underwater exploration, bioluminescent creatures, alien ocean world, Subnautica, Subnautica Below Zero, icy landscapes, survival gear, futuristic submarines, aquatic flora, diverse biomes, research bases, thermal vents, deep-sea diving, resource gathering, crafting tools, sea monsters, Leviathan class predators, thermal suit, snow fox hoverbike, alien artifacts, research outposts, crystal caves, thermal lilies, penguin-like creatures, alien penguins, high-tech fabricator, 3D holographic map, first-person view, immersive experience, ambient lighting, realistic water physics, coral reefs, kelp forests, underwater volcanoes, icebergs, alien sky, twin pack adventure, seamless transition, exploration and survival, advanced base building, underwater cinematography, dynamic weather, arctic survival, thermal activity.