Welcome to the world of No Man’s Sky © Hello Games

The Korvax alien in front of us is not amused. It waves its arms, shakes its head, shouts something in an angry manner, clearly wanting us to go. But why? All we've done so far was land on this ice planet, called Balari V. It's a bit like like Hoth, only with dinosaurs instead of AT-ATs. We haven't brought arms, or smallpox. We're just here for a little nose around. Why so bitter?

Technically, of course, we’re the alien in this scenario, and in No Man's Sky in general. But now's not the time for semantics: it's 165 degrees below freezing, not really the place or time for a space holiday, and the icon on the left side of the screen is telling us more and more angrily that our battery juice is running low. It's getting colder, the screen starts to freeze – it's time to find shelter. That's how we've made first contact with a new, irritated species.

Now, such are your options in the open universe of No Man's Sky that we could have just lobbed a grenade and let it explode in front of a hill to create a little impromptu cave to warm up in. That's the Minecraft way of thinking, and you'd be surprised how often it works in this game. But because we're still treating this as a galactic exploration and trade simulator at the preview event, this never actually occurs to us at the time. So instead we walk into a nearby house and that's how we bump into the Korvax, a seemingly friendly alien standing at his desk, waiting for customers.

He's randomly generated, to some degree, but could easily have been dreamed up in Skywalker Ranch. The Korvax starts talking to us, and we get some Mass Effect vibes with all the dialog boxes of gibberish that start appearing. Either we pick the wrong option, or this is a local shop for local aliens, because suddenly he turns hostile on us.

"Looks like you've insulted him, I like that," a most definitely human male in a red Lumberjack shirt comments over our shoulder. His name: Sean Murray. His mission, as managing director of British indie studio Hello Games: creating the biggest game of all time with a tiny team, but no pressure. No Man's Sky is a game that reinvents itself every time you boot it up.

It's rare that a game can surprise its creator, but such is the nature of the No Man's Sky universe, which is procedurally generated and uncovered as players traverse it. Murray suggests that we have to learn the Korvax alien's language first to start interacting, and then maybe we can start trading. Later we can become friends, probably have a drink and maybe even build up a trade or even military alliance, because like the name suggests, No Man's Sky is not just about aliens, dinosaurs and survival on planets, it's about going to space, playing Star Wars and becoming the new Han Solo. Hopefully. Murray can't say for sure: like its storied development, everything is rather unexpected in this game.

Just a few of the thousands of animals © Hello Games

From highs to lows: The reveal and the flood

Like any self-respecting universe, No Man's Sky started with a big bang, though Murray puts this one down to Geoff Keighley, host and producer of the Video Game Awards, rather than a massive, dense cloud of gas. Without his gentle pressure, it would have very likely not seen the eyes of the world on December 7, 2013 for the first time.

"We were incredibly nervous. We were sitting on a plane to California and no one said a word for 13 hours," recalls Murray. "To be honest, I tried hard to pull the game from the [VGA] show. I felt like the timing wasn't right. As a proud dad, you never feel like the time is right to show your baby to the world. But Geoff convinced us to do it anyway."

No Man's Sky turned out to be the star of the night and the talk of the town, and the internet. Twitter blew up, Reddit blew up, Murray's mailbox blew up with interview requests from press. That was perhaps the most daunting new challenge: Hello Games were still a tiny indie studio, after all, not even 10 people at the time, and without a PR manager to handle all the requests pouring in.

"It was weird and awesome," Murray recalls with a giggle. "Before that night, very few people knew us. We'd made a game called Joe Danger before, where a little stunt guy drives funny parcours with his motorcycle. It was kinda successful on Playstation Network, Xbox Live and iOS. But we certainly weren't in the limelight of the press. Now people were asking us for selfies at the airport."

Interview requests weren't the only thing to come flooding in however: a disaster was on the horizon. Almost exactly one year later, during a particularly heavy storm, Murray received a puzzling message on his phone, telling him that 'there was a little bit more water than usual in the streets' of Guildford, the Home Counties town in which Hello Games are based.

When Murray arrived at the studio, it was already flooded. MacBooks were floating, as was a ton of concept art. "It was tough, not going to lie,” Murray tells us. "Grant Duncan, our lead artist, loves to draw his concepts on paper, they get digitalized later – that was all gone. It was quite an emotional moment for me too, because a lot of toys got destroyed. Stuff like my good, old SNES. Nothing important really, but still kind of close to my heart. If you are an indie, a studio is not just a place to work, it's home."

Press to restart: The reboot of Hello Games

In retrospect, Murray reveals, the flood served a purpose. "It was also kinda cool, in a weird way. You know, throwing everything in a bin and just starting new. It felt like a fresh start. For us as a team, it was horrible, but also a very bonding experience. There was a good buzz and maybe I should play for sympathy a bit more here, but now we have a much nicer office, with more colour on the walls, and it feels like home again. The only thing is that we had to work doubly hard to get up to speed again."

Murray actually turned down donations from concerned fans and supporters, who asked him via Twitter how they could donate money. Instead he redirected them to a flood help fund for the whole of Britain. "It would have been super weird for us to take money, since we still had our comfy beds in our comfy homes. Other people had lost way more, so they needed the money more."

For his team it was back to work, and to speed up the process they invented some new techniques on how to do bug fixing using drones. In-game drones. "Since all of our 18 quintillion-and-a-couple planets are procedurally generated, we need to make sure that worlds that are somewhat close to each other offer a little bit of variety, and obviously as few bugs as possible. So we've programmed drones."

These tourist drones go from planet to planet, making selfies and providing GIFs of what they find for the team to check. Don't hold your breath though to see them all, because according to the math geniuses over at Kotaku Numbers it would take an estimated 584,942,417,355 years to visit each and everyone.

But how do the planets actually get generated? According to Murray, No Man's Sky's engine first drops resources on these worlds and then determines what kind of animals will live there. Hello Games has invented an algorithm that scans the bone structure of an animal and combines them with different heads, feet and necks from other species. After that, the system alters the bone structure so that every animal we've seen so far looks like it was designed by hand. Even the sound of their voice matches the volume of their body. And they are not just there for show: they genuinely appear to live their own lives.

So far in our play session we've encountered an Ewok-like creature that was at least seven feet in height. He was on foot, apparently searching for his family. When he found them, they hugged each other and made a an adorable little dance. On this planet, night is as dangerous as you might expect: it's the time when carnivores get red eyes and a hankering to hunt. You can shoot at them and loot them with your 'multi-tool', a weapon that looks like Kirk's phaser, but you can specialise it for long or short distances.

On another planet we find a race of robots, praying to some form of sun gods. As it turns out, the robots work as slaves for an artificial intelligence, controlling an entire army of drones to protect their resources. While there is an almost infinite amount of stuff to discover in this game, it's reassuring to find that there is a lot of depth behind each and every gameplay mechanic too.

No Man’s Sky is a game on a scale to seen before © Hello Games

Han Solo to baby Death Stars: The economy of No Man’s Sky

Depending where you land, No Man's Sky looks like a fantasy world, something from another epoch. With lush forests and grass in the shiniest green plains you can imagine, in its most beautiful moments the game reminds us more of a painting with no end, a digital canvas of vasts scope. But Murray is keen to stress that his project is not just an art game. "It's about survival, but also fighting, trading, maybe even calculating," he says.

Murray likes to tell stories about growing up on a farm in the Australian outback. He spent more time with books than with people; today he is a an expert mathematician as much as he is a game visionary. Maybe that's why there is a surprising amount of economics in No Man's Sky. There's a world market, that determines prices for resources, so you can harvest them on planet A and sell them in a different solar system far away, because they have more demand than supply, which means you can ask for a higher price.

As you'd expect, though, there's a cost and a risk for doing so, as we soon discover when we try our hands at a bit of merchant navying. We have to pay for the fuel of our ship, so we need to calculate first how far away the next intergalactic space trading station is – you can't miss them, they look like baby Death Stars – and if we earn more money with our products than we have to invest. We can buy brand new ships, from explorers that are very fast but with light cannonry, to ships that look like X- and Y-Wings, and even freighters that remind us of nothing more than chubby Millennium Falcons. There are thousands of variations of them – all procedurally generated.

No Man's Sky is a mind-blowing experience, because every single element has gameplay depth behind it. It's the magnitude of its feature set that makes No Man's Sky a game with galactic potential. We don't just shoot other ships: we have to balance energy power for shields and lasers. Lasers are great tools to melt down enemy shields, proton torpedoes are slow, but make one hell of an impact. They are great against freighters, in case you choose a career as space pirate.

Importantly though, no single ship can do anything – if you want to be Han Solo, you need a lot of space in your cargo ship, which means you are slower than lightweight counterparts. And if you choose to attack bigger ships to loot them, don't forget that the freighter A.I. loves to call the cops – space police appears in heavy force with a star system similar to GTA V. One star means a couple of blue police ships check out the situation. Five stars mean there is an entire armada waiting for us. If you make it that far, you better have sorted that military alliance with the Korvax already.