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'Rain World' Is Like 'STALKER' but a Platformer and You're a Rodent

Game design looks different when you start from the middle of the food chain.

What's eating away at you today?

Maybe it's a government tax form you hid under a pile of papers for the past eight months. Or you forgot to order a present for your mother's birthday and now you're hoping the delivery arrives in time. Or maybe it's the snapping jaws of a terrifying, belly-crawling lizard that finally caught up to you with its sticky tongue and is now slowly reeling you in for the kill.


We forget how lucky we are to have escaped the food chain. There are millions of species out there, and for the majority of them life ends with grievous bodily injury. All except humans (at least those of us lucky enough to live in relatively stable economic circumstances). We hope—maybe even expect—to die old in a bed saying goodbye to our sweethearts. Our head sinks into a soft pillow while some poor creature shrieks in pain as its face is chewed off.

You'll be reminded how lucky you are as you play Rain World. It's a game that casts you as a slugcat, a versatile rat-like creature, which has been separated from its family by a flood. Your task as it's outlined at the beginning of the game is to traverse its harsh, post-industrial wilderness and reunite with your lost loved ones. You learn quickly that this will be no easy task as even day-to-day survival can be a struggle. You must set out from your safe room to find and eat enough food so that you can return to hibernation before the bone-crushing rains of this strange planet arrive.

All Rain World images courtesy of Adult Swim Games

Not only do you face death from the downpours and starvation, you'll discover that the slugcat isn't the top predator around, but is also prey to the larger creatures in the game's terrific ecosystems. In the first region, the slugcat can eat berries and bats, but will be hunted down by ghastly lizards that won't hesitate to give chase across several screens. Upon spotting slugcat, the lizards will squeeze into tight ventspaces and fall from great heights with a thud if they have to. Slugcat can throw sticks and stones at them but the only truly effective getaway tactic is to move parkour-like across the staggered tiers of the dilapidated environments. That takes practice and even then a single slip-up comes easily. Prepare to be gobbled.


Many have enjoyed watching Rain World in action as it has been developed over the years since 2011. Short clips of its horrible beasts scrambling after slugcat for it to triumphantly escape will always be entertaining. But the play experience of Rain World is often the opposite of that. For most of my 28-hour journey I felt bruised and exhausted. It's the difference between watching the BBC series Planet Earth from your comfy sofa and actually being the one fleeing from hungry lions as they stick sharp claws into your hide.

Rain World is a brutal game. It's for this reason I'm sure that half the people who play it will bounce right off it. But brutality is very much the point. The idea that emerges by the time you reach the end is that it's meant to be a game that not everyone will be able to, or even want to, finish. Programmer Joar Jakobsson and level designer James Therrien set out to make a game that, through its playerbase, recreates the Darwinian theory of natural selection. Only the most determined and resourceful slugcats will make it to the end. The rest will see their lives cut short, eaten alive or falling to their death, as the player controlling them gives up once and for all on any one of the game's extremely testing gauntlets.

This is subversive game design. We're used to games catering to our fundamental understanding of life and the way we comfortably meet our end. Good game design always gives us a chance while bad game design is unfair. In other words, traditional game design flatters our humanity, acknowledging our history of overcoming whatever stands in our way. A lot of games throw challenges at us in order to feed our fantasy of conquering their virtual worlds. But Rain World angles its world and the many challenges within from the perspective of an animal that sits in the middle layer of a food chain. It's from here that its approach to design comes from, as opposed to the privileged position of being the dominant species that we're so used to.


There are two ideas that started off as embryos at the beginning of Rain World's development that led to its current form. The first is found in Jakobsson's approach to engineering the AI for the game's creatures. "Instead of thinking 'how can I make this creature act and serve as an obstacle in the game' I went at it from the angle 'how can I make this creature behave in such a way that it can find food and move around and get back to its home before the night comes'," Jakobsson tells me. "So instead of the AI creatures just existing as a player obstacle, they exist in their own right, they exist there for themselves."

"instead of the AI creatures just existing as a player obstacle, they exist in their own right, they exist there for themselves."

Compare this to the AI that drives the enemies in, say, a typical stealth game and the difference becomes clear. There are no patrol paths to learn or instant failures upon being spotted as you try to sneak past an enemy in. It instead creates living systems that react dynamically with both the slugcat and each other. As Therrien adds, "all of the creatures in the world exist perpetually. So outside of your frame they're all still alive," he says. "They're hunting food, they're getting into territorial fights, they're finding new shelters and homes and stuff like that. So you're just sorta navigating this chaotic, roiling, alive ecosystem."


But there's a fee to pay for this. "If you design an enemy to be fun, it will be fun," Jakobsson says. This is what most other games do: they provide rigid obstacles for the player to bypass that the designer has full control over. They are predictable and don't usually have enough freedom to outsmart or surprise the player. "Whereas if you design an enemy to care for itself then that might actually be super difficult and frustrating. Which sorta is the case occasionally in Rain World," Jakobsson adds.

If you reload a level in most other games the enemies will be found in the same spot as before. That isn't the case in Rain World. This means players can have unique experiences within the same tight spaces. In the week leading up to the game's release, a handful of streamers were given Rain World to play, which gave Jakobsson and Therrien the capacity to observe the huge differences that just the game's first region can serve up.

"We had one streamer who opened up the game and the RNG wasn't with her and so it was extremely difficult. It was a bunch of no-win situations that she was presented with really early on. And she's just like 'screw this, I'm not playing this game, it's impossible'," Therrien tells me. "And then you'll have another player who'll get into it and the algorithm will provide a pretty clear path at the beginning and so they're like 'this game is pretty cool'," he adds. "So, yes, dice rolls."


While the divide in experiences evidenced by those streamers is one of the defining features of Rain World, it still needs tweaking, and its creators know this. But it's a careful balance that they're looking to hit as tipping the game too far one way could compromise the second idea that sits at the heart of the game.

The idea is something Jakobsson refers to as 'the rat in Manhattan.' It's a metaphor that guided the world and visual design of Rain World and refers to being a wild animal in an artificial or constructed environment. "A rat that lives on the subway tracks has an idea of what the subway station is," Jakobsson says, "in the sense that it knows that the train is dangerous, and the Cheetos on the track are tasty, and this particular little drainage pipe where it's living is a safe spot to scurry away to when the train is arriving." The point is that the rat knows how the subway works and how to live there, but doesn't know what it's for. "It doesn't understand the political, economical, and social reasons why humans have built the subway station, it's just way beyond it," Jakobsson says.

The idea with Rain World is to recreate the experience of being that rat. It's no coincidence that when Jakobsson started work on Rain World back in 2011, he was living in Seoul, South Korea as an exchange student. As Therrien puts it, he was a "stranger in a strange land." Jakobsson remembers being overwhelmed by the foreignness of South Korea, not being able to read anything, not quite knowing how everything worked. Now, six years later, he's translated that experience into a game in which you see through the eyes of an animal stuck in nature's cruel cycles. You emerge in that baffling world not quite knowing what you're doing, with a lot of what you discover being far beyond your understanding, but you're at least smart enough to know that it all has purpose.

It's only later in the game that players will glimpse this side of Rain World, as the underlying story unravels itself. But it's hinted at early on with glyphic symbols, mechanical gateways, and ruined buildings that exist as the background to your struggles. The idea is for the esoteric details of the environment to make you feel lost. Not only through the weird technologies and neon symbols you can't understand, but also in the level design itself, which stretches out in all directions like a labyrinth, with crawlspaces and construction poles leading to new areas separate from the main paths. You feel very much like a rat in a maze for much of the game. You either do your best to adapt and survive, or you give up on the journey altogether and let nature win. Just pray the algorithms are on your side.