Scientist Robin Ayou is dissatisfied with the official reports about the death of her sister, Samantha. Samantha died on the remote planet 4546B due to "employee negligence," according to Alterra Corporation. With Alterra withdrawing all personnel from the planet for unknown reasons, Robin smuggles herself onto 4546B and finds an arctic zone teeming with life and unexplained mysteries, some alluding to the disappearance of the starship Aurora
in the vicinity. Robin's investigations into her sister's fate leads her to meet survivors of other expeditions...some from a very long time ago, and not even human.
started life as an expansion or DLC for the original Subnautica
but, as is so often the case, developed over time into an original title. This leaves it as that sometimes confusing beast, the "stand-alone expansion," a game that is smaller and more focused than the original but is newer, so has somewhat shinier graphics and improved quality-of-life features, like a better user interface and expanded base-building options.
As with most expansions (standalone or not), it would be very easy to say, "if you like Subnautica, you'll like this," and leave it at that. That is, as far is goes, true. However, Below Zero is something of a different beast to its forebear, being both slightly more difficult and somewhat more focused on its narrative.
The original Subnautica had you (playing Ryley Robinson) as the sole survivor of a starship crash, left initially fending for survival in tropical waters and later having to find your way off the planet whilst also battling an alien infection. The narrative elements were light, mostly appearing only in PDA entries and voice logs. Still, these elements drew players deeper and deeper below the planet's surface, eventually finding a way of curing their disease and fabricating the parts needed to build an escape shuttle.
Below Zero has you arriving on the planet deliberately, in search of your missing sister, although your only way of getting there is to hitch a lift with a passing ship and bailing out when nearby, with no ultimate exit strategy. This time you land in an arctic region, which introduces a major new problem that Ryley didn't have to worry about: freezing to death. Sticking your head above water long enough to breathe is fine, but staying out of the water for a few minutes is an invitation to turn into a popsicle. Building a base and vehicles are therefore more urgent tasks than in the original game, since these provide a respite from both suffocation and hypothermia during your explorations of the planet. However, building materials have been changed slightly since the original game, making building up a base slightly more difficult. Titanium, in particular, is thinner on the ground since you have not got a thousand-metre long wrecked starship leaving a miles-long trail of titanium parts across the biome this time around. A Subnautica veteran will overcome these issues in short order, but newcomers may find a game with a tricky difficulty curve.
As with Subnautica, the early part of the game is spent building up resources and building your initial tools, starting with a knife and expanding to torches, a base-building nano-device and small vehicles, like a "Seatruck," which can be expanded later on with additional modules (thus combining the functionality of the both the Seamoth submersible and the giant Cyclops submarine from the original game). Acquiring more tools and more equipment allows you to dive for longer and travel further across the map, eventually discovering the various Alterra facilities your sister was working at. Finding clues in each base leads you to the next location of note. Below Zero's selling point is that at several points your mission will lead you onto land, onto the massive frozen landmasses that envelop the map around its northern edge. Avoiding freezing is even harder than avoiding suffocating, requiring you to use vehicles (like the trusty Prawn Suit, returning from the OG game, or the new Snowfox hover-bike) or make judicious use of spicy food or standing next to hot springs.
All of this is mostly fun. Things are enhanced by a larger array of base-building options, with large, multi-purpose rooms and control rooms (allowing you to control power distribution and the visual theme of the base better) now available. The developers have also dramatically upgraded the game's engine, with slightly better graphics, far less crashes and clipping and some nice new options, like the ability to pin ingredients to your screen to stay on top of the things you are looking for. A new handheld scanner also makes locating minerals easier, though its range is extremely limited.
The traditional Subnautica gameplay loop - find, build, explore, repeat - remains compelling, but Below Zero does have a few limitations which means it's not quite as exciting this time around. The first is that Below Zero is a smaller game. The area of explorable ocean and seabed is much smaller and it's not as deep a game. Literally. In Subnautica you could drop down about two kilometres below the planet's surface, but Below Zero barely reaches half that, and there's not much in the deepest areas that require you to stay down there. This combination means that there's no Cyclops super-submarine - it literally couldn't fit down the crevasses leading to the deeper biomes - commanding which was possibly the single greatest thing about the original game.
In addition, exploring the surface arctic biomes is initially a refreshing change, but rapidly becomes more tedious. It's too easy to get turned around and end up walking in circles, and the various hostile creatures you encounter (the Snow Stalkers and Ice Worm Leviathans) are more inconvenient than actually dangerous. It's also a shorter game, easily completable in under 30 hours, whilst the original game took at least 40 hours to polish off and there was greater encouragement to do optional tasks like building bases in every biome or exploring more for the sake of exploration. You can still do stuff like that in Below Zero, but the much smaller map means you'll exhaust the game's opportunities pretty quickly.
I did enjoy Below Zero's more present story. The original Subnautica could be very obtuse in letting you know what your next goal actually was, whilst Below Zero makes it clearer through voice logs and even (gasp) actual cutscenes and conversations with other characters what your next goal is. The same dual mission structure as the original game is in play here as well, with you originally having to cure an alien plague to shut down a defence system before you could escape the planet. In Below Zero you have to find out what happened to your sister, complete her mission and then deal with a secondary objective related to various alien ruins on the planet. Those who enjoyed the sparseness of the original game (where your character never spoke, unlike here) might feel the story more intrusive here, but in reality the game is still 95% you doing your own thing to 5% story, as opposed to the original game's 99% to 1%. I also enjoyed the fact that there's more friendly flora and fauna, like the Sea Monkeys who are an initial annoyance but later help you find resources.
Subnautica: Below Zero (****) is not Subnautica 2, but it is a fun, enjoyable game that takes the original game's appeal, sands off some of the rough edges and introduces some quality of life improvements that make the game flow better, as well as featuring a better story. However, it does also struggle with a slightly steeper learning curve than the original game, the absence of some fan-favourite creatures and vehicles, and a significantly smaller map. I would certainly recommend that newcomers start with the original Subnautica before moving onto this game. Below Zero is available now for PC, PlayStation 4 and 5, Xbox One and X/S, and Nintendo Switch.