Subnautica, the underwater survival game about being a space castaway, is crawling out of its early access shell and into a shinier full release shell tomorrow. It’s been in development for four years and it is “pretty close to done”, says Charlie Cleveland, director of Unknown Worlds Entertainment. But there are plans for post-release additions, including the possibility of an icy biome with new creatures and frosty hazards. These plans aren’t final, said Cleveland in an interview with us, but he also says they are “80-90 percent sure” they’re going to make a paid expansion of some kind or another. Read on for more details and essential context that I, a dastardly journalist, cannot communicate in an intro.

First of all, the focus for the team is still on the release version, he says. When asked if the team was going to add new biomes or creatures post-release, or if they were eager to move on to something new, Cleveland said “a bit of both”.

“We’re going to see how 1.0 does,” he says. “Subnautica is a very expensive game. People think we’re super indie and I guess we kinda are but it’s, like, probably a nine million dollar game to make. If we just have the team making new biomes and stuff, and we’re spending millions of dollars to do it, we really have to make sure it pays off. So we’re going to be watching release closely.

“We’re about 80-90 percent sure we’re going to make a paid expansion. I don’t know how many we want to do but there’s one in particular we want to do that I think would fit really well with the game. So we’re planning on doing that.

“I know we’re going to do maintenance patches and stuff like that to the main game, and we’re probably going to add some small things but this is not like a ‘game as a service’ where we just keep adding to it, it’s a singleplayer game and it’s pretty close to done.”

But what exactly would the new stuff be?

“New biomes,” he says, “and fill[ing] out the story in different ways. We were talking about doing an ice world, like an Arctic area. I don’t know if we should talk about that now because we want people to just focus on release but we definitely could chat about that more when we have stuff to show. But yeah, we’re excited about that.”

A frozen biome is an idea that the developers have previously explored in their roadmap Trello (the studio’s noticeboard that anyone can go and examine). They’ve even compiled a list of ideas for creatures, equipment and some sub-zero phenomenon they’d like to see, including a swordfish, an algae bomb and salty ‘brinicles’ (as seen in BBC’s Frozen Planet). I am particularly frightened of the description of the “Atramentous Expanse”.

Atramentous Expanse – This section is dark as ink, below several meters of solid ice, blocking out all light in some areas. It lacks bioluminescence due to the freezing temperatures, and is host to maze like ice cavern systems, and biofilms which are both deadly and attracted to light sources. Due to limited visibility, underwater UAV systems are used in order to monitor and report incoming danger.

There’s a lot of neat ideas in that Google Doc but, again, it is just a Google Doc for now. We haven’t seen any of it implemented in-game, and there’s no guarantee it will appear. But let’s hope.

Cleveland also discussed mods and the possibility of multiplayer, both of which are more or less a “no”. Where modding is concerned, he’s worried supporting this would be a lot of work without much reward.

“We made the game we wanted to make with Subnautica, so it’s less exciting for us to spend a bunch of effort to have the community undo it or to make splintered versions… I love mods, but I don’t see the point.”

He does mention a somewhat janky co-op mod somebody made after decompiling the game (“I don’t know how the heck they’re doing it”) but says that although there may be tentative steps within the studio to see if it is feasible, official multiplayer is “probably not going to happen”. So don’t get your hopes up.

We’ll post the full interview with the director later in the week, in which we talk more about the horror and tranquillity of the open ocean. We’ll also have a review of the final game tomorrow. So keep your peepers open for those.