If diving beneath the surface in the original Subnautica was a precarious leap of faith into the unknown, navigating the depths of its standalone expansion, Subnautica: Below Zero, feels more like returning home after a long trip away.
Having already spent dozens of hours amongst the marine life of Planet 4546B in Unknown Worlds' 2018 survival hit, I'm no longer a stranger to its charms and perils, even if Subnautica: Below Zero takes place in a much colder (and thus ecologically distinctive) region of the planet's oceanic surface.
My love for the first Subnautica, however, may also help explain why Below Zero's failure to enrapture me in the same way hurts all the more. While I enjoyed my time with the game's 15 odd hour campaign, its resonance never lingered beyond the moment I put the controller down after another session beneath the sea.
Subnautica: Below Zero's familiarity doesn't breed contempt, but it certainly suggests that Unknown Worlds has now reached the seabed of Subnautica's potential, despite still managing to conjure up moments of wonder and dread beyond the shore.
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Subnautica: Below Zero seems to misunderstand what made its predecessor so impressive as a survival game. At the beginning of Subnautica, you crashland onto the waters of Planet 4546B with little to no information about who you are, how you got there, or whether there's even a potential way off this aquatic abyss.
The answers to those questions are slowly drip-fed to the player through their own discoveries, but that larger narrative is backgrounded against the more immediate and compelling watercooler moments drawn from exploring Subnautica's world. Sure, it's interesting to learn about the true nature of your stranding on this planet, but narrowly escaping a Reaper, or first setting eyes upon a pod of Feedback Whales… these were the experiences that kept me coming back.
Subnautica: Below Zero goes in the other direction, pushing its plot to the front of your adventures at the expense of letting the miasmic mysteries of its world tell its own stories. With full voice acting, NPC interactions, and a defined set of narrative beats, the expansion offers a survival experience that's more choreographed in structure, and – to its credit – that's not an entirely bad thing.
Unknown Worlds gets to explore more of the science-fiction backdrop it first established with Subnautica, for example, colouring in the exploitative Alterra Corporation with more nuanced and satirical shades of nefariousness (motivational posters are considered contraband within on-planet research stations). Kimberly D. Brooks, meanwhile, brings heart and humanity to new protagonist Robin, and her quest to figure out what happened to her sister on the frozen tundras of 4546B isn't without its moments of emotional payoff.
But that story is often too keen to maintain control of what should be a self-guided survival adventure. Once Robin's consciousness is invaded by a sentient superintelligence known as an Architect early on in the campaign, the pair's inner dialogue remains a constant throughout the rest of the game, used to either contextualise discoveries with exposition and lore, push the player towards the next objective, or generally break the sense of isolation that was so pervasive in its predecessor.
That's a shame, because that isolation was exactly what made the original Subnautica so evocative as a survival horror game, especially since the harrowing sound design of its ocean comes to life when the talking stops.
Below Zero features less frights than its predecessor overall, in fact. While Unknown Worlds has introduced a number of new Leviathan creatures for Robin to contend with, the story's tendency to interrupt the immersive ambience of its environments imposes a degree of attentive distance from its threats. That's not to say I didn't fear the appearance of Below Zero's predators, but their sudden arrivals didn't launch me out of my seat as it might have done in Subnautica, since I was never as totally drawn into its world in the first place.
While Subnautica's identity as a horror game may be somewhat… *ahem* watered down in Below Zero, its crafting mechanics have only been improved and enhanced. Unknown Worlds has expanded the suite of tools and resources available to the player, allowing them to build more elaborate sea bases, experiment with new toys such as the Spy Pengling, and explore its shores with a range of customisable vehicles. The sea train is a particular highlight, as a mobile base of operations that offers versatility, convenience, and (relative) security for the more ambitious excursions into the planet's depths.
Below Zero also performs a lot better than its counterpart, with less texture pop-ins, framerate drops, and hard crashes, at least on PS5. Unknown World's sublime art design has not lost any of its charm, either, expertly utilising colour washes, lighting, and fauna to conjure up a breathtaking world beneath the surface, giving each biome its own identity while juggling moments of awe and fear within them.
It's just disappointing that the potential highs of those moments are so often held back by a narrative that never quite chimes with Subnautica's potency as a survival-horror oriented open world. Unknown Worlds took a gamble with Below Zero, seeding in a story that attempts to provide direction and momentum to the player's exploration of its seas. That gamble hasn't quite paid off in the way that I had hoped, however, resulting in an ocean that's just as beautiful as before, but lacking the sense of danger and mystery that kept me diving back in the first time around.