Subnautica: Below Zero review

Subnautica: Below Zero a worthy follow-up to one of the best survival games on the market

Subnautica Below Zero review
Editor's Choice
(Image: © Unknown Worlds Entertainment)

Tom's Guide Verdict

Subnautica: Below Zero is a solid addition to the survival game genre, delivering a standalone experience that manages to be both cozy and challenging.


  • +

    Unique gameplay

  • +

    Well-designed emphasis on exploration

  • +

    Beautiful environment and diverse sea life


  • -

    Smaller map compared to its predecessor

  • -

    No multiplayer

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After spending two years in early access, Subnautica: Below Zero has finally arrived. A follow-up to one of the most critically acclaimed open-world survival games, the sequel brings with it brand-new challenges and chilling adventures. 

Full disclosure: I’ve never played the original Subnautica game, released in 2014. However, playing through the entirety of Subnautica: Below Zero definitely made me regret not giving the series a go sooner. 

In our Subnautica: Below Zero review below, we highlight what we loved about this survival sequel, including its unique gameplay, unobtrusive story and well-designed environments. And if you’re on the prowl for more new games, take a look at our list of the best PC games of 2021. 

Subnautica: Below Zero review: Gameplay

Subnautica: Below Zero is a survival game built on the foundation of deep-sea exploration and resource gathering. Crash-landing in the arctic region of an aquatic planet called 4546B, you start off with some basic equipment, including an frustratingly primitive oxygen tank that can only hold 45 seconds’ worth of air at a time. That means you’ll constantly have to swim up to the surface to avoid drowning. 

(Image credit: Unknown Worlds Entertainment)

As the name of the game may indicate, the planet’s terrain is inhospitably cold, preventing you from seeking shelter in the overworld without succumbing to hypothermia. With the threat of death looming from both sides of the water, this game constantly toes the thin line between comfort and adventure. 

(Image credit: Unknown Worlds Entertainment)

Unlike more combat-driven survival games, exploration is the principal activity in Subnautica: Below Zero. Self-defense isn't much of a concern, considering most of the sea life around you is either a harmless fish fry or a colossal monster, which you have no business fighting. Instead, your primary task is to scavenge the seafloor for various raw materials. You can use these resources to construct underwater bases and more advanced tools, which enable you to descend even deeper.

(Image credit: Unknown Worlds Entertainment)

You can bypass virtually all of the game’s challenges, including thirst, hunger, and lack of oxygen by playing the game in Freedom mode. This variant allows you to focus solely on exploring the vast blue ocean. There’s also Creative mode, which enables you to start the game with all resources and invention blueprints readily available. However, I would thoroughly recommend opting for Survival mode for your first several playthroughs in order to get the most authentic Subnautica: Below Zero experience. Returning fans and more seasoned survival players also have Hardcore mode at their disposal, introducing the exciting risk of having your entire game file deleted permanently should your character die.

(Image credit: Unknown Worlds Entertainment)

Unfortunately, Subnautica: Below Zero doesn’t offer multiplayer, which I think could have added a bit more depth to the game. The developers had previously explored the possibility of adding co-op gameplay to both the original Subnautica and its sequel. However, they ultimately scrapped the idea to focus on more important aspects of the gameplay. 

Subnautica: Below Zero review: Plot

In Subnautica: Below Zero, you take the reins as a sharp scientist named Robin Ayou, as she investigates the mystery surrounding the death of her sister, Sam. According to Alterra, the interplanetary corporation that employed Robin’s sister, Sam had reportedly perished in an accident on planet 4546B due to her own negligence. Robin, as a loving sister, takes Alterra’s report with a grain of salt, and decides to conduct her own inquiry. 

Overall, the game’s plot is there to support the exploration-based gameplay, and it's paced well. The story appears throughout your adventures in an unobtrusive way, as you collect audio logs during your numerous ventures across the planet. The beauty of Subnautica: Below Zero is that you’re free to be as engaged with the lore of the game as you want. You can choose whether or not you want to listen to the audio logs for more details regarding Sam’s untimely demise. 

(Image credit: Unknown Worlds Entertainment)

Conveniently, the story's biggest and most relevant revelations are unmissable, since they’re present throughout the game in the form of cutscenes and monologues. As you continue to make technological advancements and explore your surroundings, key plot locations will also become available on your radar. Even if you somehow come across plot locations earlier than you’re told, the game will adjust the story to suit your discoveries.

Subnautica: Below Zero review: Environment

At first glance, the map in Subnautica: Below Zero can feel almost too overwhelming to explore properly. However, the more I played, the more I realized how cozy and well-designed it was. There are very few underutilized spaces within the game, as each unique area of the map contains something that will be relevant to your progress.

At the same time, I found the environment design to be incredibly immersive. It does a great job of recreating the isolation you’d expect to feel being left alone in the deep blue sea to fend for yourself. However, as you gather more materials and craft new modes of transportation, your surroundings will become easier to explore. After approximately five hours of gameplay, I found myself reaching the edges of the map on more than one occasion, which only incentivized me to invest in equipment that allowed me to start diving deeper and deeper into the ocean. 

(Image credit: Unknown Worlds Entertainment)

Subnautica: Below Zero also features a wide variety of different biomes for you to explore, giving you the chance to encounter new flora and fauna wherever you go. The sea life you come across on 4546B is incredibly diverse, too, ranging from small and passive herbivores, to aggressive shark-like creatures that attack on sight. You’re also bound to cross paths with playful sea monkeys, which can and will steal your tools from you when you least expect it. 

(Image credit: Unknown Worlds Entertainment)

The game’s picturesque scenery and colorful plant life will mean that you’ll likely never want to stop exploring. In fact, while most survival games will have you cowering in safety during the night, the beauty of Subnautica: Below Zero will encourage you to continue traversing the dark seas with bioluminescent marine life. The sound effects are a great addition to the game, too, with the odd distant snarl of a shark popping up in your headphones every once in a while to keep you on your toes.

Subnautica: Below Zero review: Verdict

Subnautica: Below Zero successfully combines everything that makes a great survival game tick. With an incredibly immersive environment, a diverse roster of sea creatures and an unobtrusive storyline, this sequel has its fair share of adventures for players willing to take a chance in 4546B’s sub-zero temperatures. 

Overall, the game is a must-play for fans of the survival genre. Even those, like myself, who are new to the franchise will enjoy the unique gameplay that Subnautica: Below Zero has to offer. At the same time, fans of the original game can challenge themselves to survive in an unfamiliar setting, as long as they can stay warm.

Denise Primbet
News Writer

Denise is a Life Reporter at Newsweek, covering everything lifestyle-related, including health, relationships, personal finance, beauty and more. She was formerly a news writer at Tom’s Guide, regularly producing stories on all things tech, gaming software/hardware, fitness, streaming, and more. Her published content ranges from short-form news articles to long-form pieces, including reviews, buying guides, how-tos, and features. When she's not playing horror games, she can be found exploring East London with her adorable puppy. She’s also a part-time piano enthusiast and regularly experiments in the kitchen.