Count my troubles: Rowan perished from carbon dioxide poisoning while on a daring mining expedition, because I'd forgotten to build an escape ladder. Marie, finding that the outhouse was clogged, peed on the floor and polluted my newly constructed water supply. One time, I made an oxygen generator, but I put it near the top of the colony, like a fool, with utter disregard for the fact that carbon dioxide sinks. In one run, I spent so much time designing bedrooms that I simply forgot to make a farm, because I assumed the storage box by the colony portal would have more food than it ultimately did. And then I planted seeds that would never grow in the pressurized atmosphere—and created mass famine.

Oxygen Not Included, the latest slice of survival weirdness from the developers of Don’t Starve, drops you off in a barren base camp at the center of a barely hospitable planet. You have three "dupes," little humanoids who require oxygen and food to stay alive. Sounds simple, right? Nope. In my first playthrough, everything went wrong. It was a disaster. Which is, of course, the point.

The game's release to the public will signal the end of just over two years of early access. During that time, I've played more than 100 hours. I'm all in. It's different than any survival sim I've ever played, thanks to its baffling complexity.

Klei Entertainment has once again demonstrated its sublime mastery of the survival sim genre. It's a perfect game for anyone who loved Don't Starve, which also required a complex understanding of resource management and progressively more difficult crafting, but made it fun through weird quirks like evil trees, ever-stranger monsters, and pig towns in constant combat with massive spiders. Oxygen Not Included takes these Klei principles, and extends them magnificently through punishing difficulty—and constant struggle against mortality—tempered by the same level of personality, art style, and environmental variety.

More than anything, Oxygen Not Included is a systems engineering sim. You'll do everything from water and waste management, to subsistence farming and ranching, to gas ventilation and power generation. Your dupes have adorable, multipurpose ray guns that can mine resources from the environment in a two dimensional grid, where each dig yields a resource in a Minecraft like way. In the early days, you'll make a farm, create a generator, build a water pump, and mine algae in order to create oxygen. As those resources dwindle, you'll research and pivot to other machinery that replaces those items but creates other toxic outputs.

Oxygen Not Included is not content to stop there; it also requires players to manually wire, pipe, and vent every machine on the map. It's not enough to build a shower—you need to pipe it to a water tank, generate electricity for said water tank, wire it all up, and design a filtration system. As the game progresses, you'll have to do more and more of this, making life in the colony increasingly precarious. It's very easy to make a mistake that forces your dupes to shower in pee water, infects everyone with food poisoning, or suffocates the entire colony in their sleep. Not that I would know from personal experience.

Like Don't Starve, the process of survival is utterly hilarious. The easiest to grow food is meal lice, a gently oscillating plant that produces a single "louse" (which, when minimized, looks like a tiny croissant). You can use a "microbe musher" to smash a few into a vile "liceloaf" nutrition bar, which your dupes will hate eating—but you're going to feed it to them anyway. Much like beefalos can be shaved in their sleep, Oxygen Not Included lets you harvest wool from furry little dreckos.

Oxygen Not Included takes into account even more detail than this, too. There's a thermal overlay, wherein you can see your machinery's heat runoff and attempt to keep it from wreaking havoc on the rest of the delicate ecosystem you've just built. There's also a decor overlay, which shows how aesthetically pleasing your base is to your dupes, and "room" overlays which highlight spaces—mess halls, bedrooms, bathrooms—that will rejuvenate your dupes by imparting "morale." The quality of the art, and how much it boosts morale, is dictated by the artistic talent of the dupe that made it. Sometimes dupes are terrible artists, leaving your base with hideous blobs of marble.

But again, messing up in Oxygen Not Included is a lot of fun. Dupes come with generated names, but you can rename them whatever you like. As you grow your colony and develop their careers, dupes become valuable assets. They each have strengths, which translate into professions. "Learning" translates to research and "digging" translates to, well, digging. They get fabulous hats for each profession. Dupes also have distinct preferences, aversions, and ailments, like the "trypophobe," who absolutely refuses to be a miner, or the narcolept who will randomly fall asleep in the middle of doing a task. The portal at the center of the base glows every three days giving you the option to select either an arbitrary resource or a new dupe, and the tradeoff between their labor value versus food and oxygen consumption is at the heart of the game.

When morale dips too low, dupes exhibit "stress reactions," which can be everything from vomiting to binge eating to excessive crying. If you're wondering how bat shit this game is, let's just say that I prefer the criers, because at least the tears can be swept up, bottled and reintroduced into my water reservoir. You'll likely be mapping all of these systems earlier than you're comfortable, because the game starts you in such a precarious position. (The game's interface has a steep learning curve, even with early "help" prompts.)

Dupes will also regularly go offscript if you're a bad urban planner, which is a great motivator. My dupes have eaten dinner in a clogged outhouse; suffocated while harvesting plants; stress vomited while running on a wheel style generator; cried while ranching because I built the graveyard too nearby. (Yes, dupes can die; yes, you can build them graves; and yes you watch the dupe carry its fallen brethren to the grave like an ant. I have even witnessed a dupe die while carrying a dead dupe.) Dupes also hate most of the readily available foods you can make them, and will gag and scrape their tongues after eating. They sleep on the floor (or on a ladder!) if there aren't available cots. If the outhouse is unavailable, they'll just pee on the floor. It's all so darkly comic, the same way it was always tempting to destroy part of a rollercoaster, in Rollercoaster Tycoon, while passengers were already on it.

The game's planning and continual maintenance may not seem enjoyable, but for the right kind of brain, it's intensely fun, each challenge providing fodder for another few days of obsessive fabrication and research. With each new "cycle" comes a new way of souping up and expanding your base—and more ways to die of something terrible, like getting entombed in dirt, or of something frustratingly complex, like a plant being .5 degrees too hot to harvest… with no tools to cool it down.

These unique gameplay wrinkles makes each death feel like an iterative process towards doing just a little better next time. And with each cycle lasting roughly 11 minutes—with the option to double or triple the speed—it's easy to play for "just one more day." I have let the resource management of my own life fall to the wayside in order to provide for made up dupes, and I have no regrets. I love my humanoid children with my whole heart.

The game I’ve been playing in early access for the past year and a half has felt like an even more potent version of this; it let me indulge the belief that my inability to create a good base had more to do with bugs than my terrible urban planning. I played the game before a jobs system was established, which meant I had to constantly pause the game to delegate tasks to individual dupes. I played before there was a good priority system for tasks, which meant dupes would do high priority dig tasks rather than save themselves from starvation by eating available food. Now that the game is closer to being fully ironed out I've sunk even more time into it, determined to build an HGTV worthy base.

Thanks to Klei's well documented history of adding DLC—they’ve been adding more and more stuff to Don’t Starve for years now—I doubt I'll ever tire of Oxygen Not Included's punishing virtual worlds. I'm hoping for expansions that will give my dupes new landscapes to roam, swanky outfits to wear, and fluffy creatures to ranch. Maybe this environment ruins all of my crops or forces my colony to endure getting roasted alive by steam vents—but that's all part of the process.