Confession time: I never actually finished the original Subnautica. It’s not that I didn’t love its clever mix of sandbox survival and structured narrative; it’s just that I’m a massive wuss when it comes to the sea. Or what lies beneath, at least. Subnautica’s sun-kissed Safe Shallows? Fine, lovely. Kelp Forest’s increasing murk? Nerves starting to tingle. The yawning abyss of oceanic horrors pretty much everywhere else on the map? Bollocks to that. Let’s just say I played most of the original cresting gingerly along the surface trying not to think too much about what might be lurking below. So when I finally reached the point the only way left to go was down, well, that was me done. In other words, I could immediately see the appeal of Subnautica 2’s co-op companionship, the reassuring sense of safety in numbers, the moment it was announced.

Subnautica 2, of course, finally launched into early access last week, some four years after its initial reveal. And it arrives amid a high-profile legal tussle between ousted leadership at developer Unknown Worlds and the studio’s owner Krafton. But as incredibly messy as that drama is – court proceedings included the frankly mindboggling allegation Krafton’s CEO attempted to wriggle out of paying a promised $250m fee to Unknown Worlds by consulting ChatGPT for advice – that turmoil certainly isn’t reflected in-game. Subnautica 2, co-op and all, is an impressively assured start.

That probably shouldn’t be a huge surprise, though. Third time around – after Subnautica 1 and Below Zero – Unknown Worlds has its underwater survival formula down to something of a fine art. This is a game that nails its sense of nautical exploration and discovery from the off; filling the ocean planet of Proteus – or the bit available in early access, at least – with remarkable alien sights, skilfully arranging them in a way that beckons like a siren’s call. Most obviously, there’s that gargantuan fungus-tree, spearing out the water and looming over all (and no, I’ve not been over there yet, given the lingering trauma from exploring the Aurora’s wreckage in Subnautica 1). But there’s intrigue everywhere: strange spires peeking tantalising out the water on the distant horizon; derelict bases stacked high against narrow ravine walls like a half-formed underwater city; thick tendrils snaking around rocks like the veins of an unseen titan, and more.

Already, it’s a convincing, convincingly alien space, with Unknown Worlds once again using the breadcrumbs of a story to nudge players outward and gently encourage exploration. Sporadically, your expedition’s dubiously reliable AI locates new beacons, and as you meander toward that next waypoint you’ll encounter yet more deliberately alluring distractions. It’s a trick that helps maintain the adventure’s shape without robbing you of that crucial sense of sandbox freedom, and the bits around it – the familiar rhythms of scavenging, crafting, and building – are as compelling as ever.

It helps, too, that Subnautica 2’s story feels like a good ‘un. As if there wasn’t already enough horror to be getting on with, there’s a touch of existential terror here as old minds endlessly download into new bodies, and hints emerge of Proteus’ genetic fluidity. It’s intriguing stuff, affectingly voiced across countless discarded PDAs, lending the game a surprisingly melancholy mood as you investigate the fates of once hopeful Pioneers. But as great as all this stuff is, I’ll admit my biggest wows so far have come from the fact Subnautica 2 is just beautiful.

Subnautica 1 had its moments, yes, but its biomes felt perhaps a little too barren, not helped by the endless murk Unknown Worlds frequently used to mask the poor draw distances and loading judder. It was a vision that always felt a little compromised, but Subnautica 2’s ocean planet reveals itself in all its gorgeous, intimidating vastness almost immediately. Yes, it adopts a similar aesthetic to its predecessors – a sort of cartoonishly stylised world of vast bioluminescent wonder – but it feels unbounded here.

Sun glints off richly detailed choral shoals in the opening shallows; shallows give way to chasms of jutting rock spires clearly visible in the distance; to darker, more terrifying corners where vicious things roam. And Proteus feels alive. Shark-like hunters circle with patient intent, bifurcated fish ready hammerhead blows, grasping terrors lurk silently beneath the sand, and all around: adorable scuttling shrimp things, weird butthole fish, and other curious fauna clustered in endlessly shifting, mesmerising swirls.

I could go on! I love the wonderfully convincing physicality of the player character despite the first-person camera – their legs and body twisting beneath you with every change in direction, arms slicing forward as you swim. And the phenomenal audio is perhaps even more intimidating than the visuals. I’m perpetually on high alert, ready to flee at the smallest sound, already attuned to the fact the subtlest shifts usually precede sudden, violently snapping jaws. I’m not joking when I say my sea terror (which I’m pretty sure can be traced back to Ecco the Dolphin on Dreamcast, but that’s a story for another day) is in constant overdrive.

So to come full circle, thank goodness for co-op, the perfect way to share your unabating nautical terror with a pal. Proteus might be a world where unscripted jumpscares await around every corner, but there’s inherent comfort in companionship: the suffocating horrors of the beckoning depths are so much easier to face when there’s a bit of banter, a friendly silhouette nearby, to diffuse the tension. And as mortifying as it might be to let out a full-throated yelp of terror mid-conversation (more than once), it’s far less embarrassing when, five minutes later, your friend does the same thing.

But honestly, while there’s undoubted pleasure to be found in the usual social rhythms of collaborative sandbox survival, and as much as I’ve enjoyed the company, co-op is, I think, a pretty terrible way to experience Subnautica 2. Even in early access, this is a game of such carefully hewed ambience – of creeping dread and lingering melancholy, of intimate discovery and lonely survival – it doesn’t feel quite right to ride roughshod over it all.

And structurally, co-op is a bit of an awkward fit. Given the way the breadcrumb narrative is explicitly designed to nudge you toward the important bits, it seems like you have to be fairly militant about sticking together if you want to maintain a shared sense of discovery and not miss out. Too often, I’d stumble across something intriguing then need to wait for my friend to come find me, so we could both appreciate the story threads in their intended environmental context. And that, I think, creates a difficult tension with the game’s looser exploratory spirit.

I’ve played about five hours of Subnautica 2’s early access so far, some with a friend and some alone. And solo absolutely feels like the right way to play; to best experience Subnautica 2’s meticulous design, its forlorn ambience, and its wonderfully alien world. But then comes another alert from my AI guide, another beacon demanding my attention. And as I swim tentatively into the unknown – the yawning abyss opening beneath me, the suffocating grip of darkness taking hold as an awful roar from some unseen titan fills the void – I think: who am I kidding? Of course I’m not bloody doing this alone.